It is working for me. Changed nopcommerce 3.8
Added the line to Global.asax.cs
protected void Application_Start()
//most of API providers require TLS 1.2 nowadays
System.Net.ServicePointManager.SecurityProtocol = System.Net.SecurityProtocolType.Tls12;
Recompiled. Deployed the updated Nop.Web.dll to the bin folder on the server.
Restarted IIS. All good!
I'm happy to help, PM me for any specific issues.