Add SSL for web application without domain registered

Question

I have a .NET winform application that connects to a remote database on a VPS (windows 2016 server), the connection is made through OpenVpn because it was necessary for certain functions to be used on the mobile phone as well, an extension was made with Angular + .NET Core, as there is no domain, access is made through the browser directly based on the IP,the authentication is done with JWT. The browser shows in the bar the exclamation mark and in details ‘Your connection site is not secure’ The application is not necessarily public, the number of users is small <10.

I don't know SSH and I said to ask you for an opinion, can the web application be secured without the need for a domain?

Is there anything free?

thank you

Answer 1

Hi,I've used the document,but at Step 3-10 (Configuration Editor) I don't have that options, just have: Collection(Count=0) and file(empty)
I put also
"ClientAuthTrustMode"=dword:00000002
"SendTrustedIssuerList"=dword:00000000 for [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL]

On browser I got 'Your connection is not secure'

thanks