Hello @Sultan Dilawar Ali , the sample you shared is using react-native-app-auth package for managing the authentication and token management and this package supports Auth_Code grant flow in the backend. Now if you check the following section "https://learn.microsoft.com/en-us/graph/tutorials/react-native?tutorial-step=3" you would find the following:
serviceConfiguration: {
authorizationEndpoint: 'https://login.microsoftonline.com/common/oauth2/v2.0/authorize',
tokenEndpoint: 'https://login.microsoftonline.com/common/oauth2/v2.0/token',
}
Here you would see that the sample is calling the /authorize endpoint of Azure AD which provides its own login page. You cannot make a lot of updates to this login page, as this is something coming directly from Azure AD. A certain degree of customization is possible and you can find the details here: https://learn.microsoft.com/en-us/azure/active-directory/fundamentals/customize-branding#customize-your-azure-ad-sign-in-page
Apart from this not much customization is possible.
Hope this helps.
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