An unhandled exception occurred while processing the request. ApplicationException:

Question

Register.cshtml

@page
@model FaceAdminApp.Pages.Auth.RegisterModel
@{
    ViewData["Title"] = "Register";
}
@if (Model.IsPhoneNumberPresent)
{
    <div class="container">
        <div class="row justify-content-center">
            <div class="col-md-5">
                <h5>NEW REGISTER</h5>
                <div class="card">
                    <div class="card-body">
                        <form method="post">
                            <div class="px-3 my-1 d-flex justify-center">
                                <div class="row">
                                    <div class="col-md-6">
                                        <div class="form-group">
                                            <label for="CountryCode">Country Code</label>
                                            <select class="form-control" id="CountryCode" asp-for="LoginModel.CountryCode">
                                                <option value="+91">+91</option>
                                                <option value="+49">+49</option>
                                                <option value="+1">+1</option>
                                                <option value="+1">+33</option>
                                            </select>
                                        </div>
                                    </div>
                                    <div class="col-md-6">
                                        <div class="form-group">
                                            <label for="PhoneNumber">Phone Number</label>
                                            <input type="text" class="form-control" id="PhoneNumber" asp-for="LoginModel.Username">
                                        </div>
                                    </div>
                                </div>
                            </div>
                            <div class="px-3 my-1 d-flex justify-center">
                                <div>
                                    <label for="OTP">OTP</label>
                                    <input id="OTP" type="text" class="form-control" asp-for="LoginModel.Password" autocomplete="off" />
                                </div>
                                <button type="submit" class="btn btn-outline-primary btn-sm ml-4 mt-4" style="width: 150px; " asp-page-handler="GenerateRegisterOtp" disabled="@Model.OtpProcessing">
                                    @if (Model.OtpProcessing)
                                    {
                                        <div class="spinner-border spinner-border-sm me-2" role="status" aria-hidden="true">
                                        <span class="visually-hidden">Loading...</span>
                                        </div>
                                        <span>GENERATING</span>
                                    }
                                    else
                                    {
                                        <span>GENERATE OTP</span>
                                    }
                                </button>
                                <div class="mt-6 d-flex justify-space-between align-center">
                                    <a asp-page="/Auth/Login" class="btn btn-success btn-sm ml-4 mt-4">LOGIN</a>
                                </div>
                                <button type="submit" class="btn btn-danger btn-sm ml-4 mt-4" style="width: 150px; " asp-page-handler="ValidPhoneNumberSubmit" disabled="@Model.Processing">
                                    @if (Model.Processing)
                                    {
                                        <div class="spinner-border spinner-border-sm me-2" role="status" aria-hidden="true">
                                        <span class="visually-hidden">Loading...</span>
                                        </div>
                                        <span>VALIDATING</span>
                                    }
                                    else
                                    {
                                        <span>VALIDATE</span>
                                    }
                                </button>
                            </div>
                        </form>
                    </div>
                </div>
            </div>
        </div>
    </div>
}
else
{
<div class="container">
    <div class="row justify-content-center">
        <div class="col-md-5">
            <h5>NEW REGISTER</h5>
            <div class="card">
                <div class="card-body">
                    <form method="post">
                        <div class="px-3 my-1 d-flex justify-center">
                            <div class="row">
                                <div class="col-md-6">
                                    <div class="form-group">
                                        <label for="CountryCode">Country Code</label>
                                        <select class="form-control" id="CountryCode" asp-for="LoginModel.CountryCode">
                                            <option value="+91">+91</option>
                                            <option value="+49">+49</option>
                                            <option value="+1">+1</option>
                                            <option value="+1">+33</option>
                                        </select>
                                    </div>
                                </div>
                                <div class="col-md-6">
                                    <div class="form-group">
                                        <label for="PhoneNumber">Phone Number</label>
                                        <input type="text" class="form-control" id="PhoneNumber" asp-for="LoginModel.Username">
                                    </div>
                                </div>
                            </div>
                        </div>
                        <div class="px-3 my-1 d-flex justify-center">
                            <div>
                                <label for="OTP">OTP</label>
                                <input id="OTP" type="text" class="form-control" asp-for="LoginModel.Password" autocomplete="off" />
                            </div>
                                <button type="submit" asp-page-handler="GenerateRegisterOtp" class="btn btn-outline-primary btn-sm ml-4 mt-4" style="width: 150px;" disabled="@Model.OtpProcessing">
                                @if (Model.OtpProcessing)
                                {
                                    <div class="spinner-border spinner-border-sm me-2" role="status" aria-hidden="true">
                                        <span class="visually-hidden">Loading...</span>
                                    </div>
                                    <span>GENERATING</span>
                                }
                                else
                                {
                                    <span>GENERATE OTP</span>
                                }
                            </button>
                            </div>
                            <div class="mt-3 d-flex justify-center align-center">
                                <!-- Adjust mt-3 for vertical spacing -->
                                <div class="d-flex flex-column align-items-center">
                                    <a asp-page="/Auth/Login" class="btn btn-success mt-4 ml-4" style="width:150px">LOGIN</a>
                                </div>
                                <span style="margin-left: 60px;"></span>
                                <button type="submit" asp-page-handler="ValidPhoneNumberSubmit" class="btn btn-danger btn-sm mt-4 ml-4" style="width: 150px;" disabled="@Model.Processing">
                                    @if (Model.Processing)
                                    {
                                        <div class="spinner-border spinner-border-sm me-2" role="status" aria-hidden="true">
                                            <span class="visually-hidden">Loading...</span>
                                        </div>
                                        <span>VALIDATING</span>
                                    }
                                    else
                                    {
                                        <span>VALIDATE</span>
                                    }
                                </button>
                                </div>
                        
                          
                    </form>
                  
                </div>
            </div>
        </div>
    </div>
</div>
}

Register.cshtml.cs

    public void OnGet(string LoginPhoneNumber)
        {
            if (!string.IsNullOrEmpty(LoginPhoneNumber))
            {
                IsPhoneNumberPresent = true;
                //LoginModel = new OtpRegisterVm { Username = LoginPhoneNumber, CountryCode = CountryCode };
            }
            else
            {
                IsPhoneNumberPresent = false;
            }
        }
        public async Task<IActionResult> OnPostGenerateRegisterOtpAsync()
        {
            OtpProcessing = true;
            if (string.IsNullOrEmpty(LoginModel.Username))
            {
                Notify.Add(TempData, false, "", "Phone Number required");
                OtpProcessing = false;
                return Page();
            }
            else if (LoginModel.Username.Length < 10)
            {
                Notify.Add(TempData, false, "", "Enter valid Phone Number");
                OtpProcessing = false;
                return Page();
            }
            var dto = new PhoneNumberDto { PhoneNumber = LoginModel.CountryCode + LoginModel.Username };
           
                var response = await _apiService.GenerateRegisterOtp(dto);
                if (response.IsSuccess)
                {
                    Notify.Add(TempData, true, $"OTP Generated successfully. ", "");
                }
                else
                {
                    Notify.Add(TempData, false, "", response.Message);
                }
           
            OtpProcessing = false;
            return Page();
        }

Service.cs

        public async Task<ResponseDto<string>> GenerateRegisterOtp(PhoneNumberDto dto)
        {
            var httpResponse = await _httpService.Post<PhoneNumberDto, ResponseDto<string>>(
                "/api/identity/generateregisterotp", dto);
            if (!httpResponse.Success)
                throw new ApplicationException(await httpResponse.GetBody());
            return httpResponse.Response;
        }

Controller.cs

 [AllowAnonymous]
 [HttpPost("generateregisterotp")]
 public async Task<ResponseDto<string>> GenerateRegisterOTP(PhoneNumberDto phoneNumber)
 {
     try
     {
         var existingUser = await _context.GetAppUserByUsername(phoneNumber.PhoneNumber);
         if (existingUser != null)
         {
             return new ResponseDto<string>(false, $"The {phoneNumber.PhoneNumber} is already registered");
         }
         var otp = new Random().Next(111947, 999999).ToString();
         var result = await _context.RegisterSetOtpAsync(phoneNumber.PhoneNumber, otp);
         if (result)
         {
            
             return new ResponseDto<string>(true, $"OTP sent successfully", "");
         }
     }
     catch (Exception ex)
     {
         return new ResponseDto<string>(false, ex.Message);
     }
     return new ResponseDto<string>(false, "Server is not responding");
 }

while genarting OTP fro new user from the server to store it to the databvse facing these below issue

• FaceAdminApp.Services.VacApiService.GenerateRegisterOtp(PhoneNumberDto dto) in VacApiService.cs +
  1. throw new ApplicationException(await httpResponse.GetBody());
• FaceAdminApp.Pages.Auth.RegisterModel.OnPostGenerateRegisterOtpAsync() in Register.cshtml.cs +
  1. var response = await _apiService.GenerateRegisterOtp(dto);