C#: How to manage Charles Proxy to trace calls from Visual Studio or Rider?

I use Charles Proxy on Mac OS, to debug mobile app: it works well on real devices (iOS/Android), on iOS simulator, but it's a little tricky on Android simulators (several IPs are used for the same URL).

However, I try to debug APIs Integrations Tests, and in this case, I don't see any trace in Charles Proxy...

I've tried to do this with Visual Studio for Mac and with Rider.

When I debug the test, I can see that the call is well done, but I don't see any trace in Charles Proxy, whereas when I use the same URL in the mobile app, I can see the trace easily.

Is there a specific step to do to include calls from console app or Integration Tests calls from any IDE? (Visual Studio for Mac or Rider)

In the same time, I can see all the traces coming from Chrome, Safari, Slack,... So I don't see what I could have forgotten.

After having edited the HttpClientHandler like this, I can see traces in Charles Proxy:

public class TestsHttpMessageHandlerFactory : IHttpMessageHandlerFactory
{
    public HttpMessageHandler Create()
    {
        return new HttpClientHandler
        {
            Proxy = new WebProxy("http://192.168.86.177:8888"),
            UseProxy = true
        };
    }
}

But now I have the following error details in Charles Proxy:

 - Status: Failed Failure: Client closed the connection before a request
   was made. Possibly the SSL certificate was rejected. 
 - Notes: You may need to configure your browser or application to trust the Charles Root Certificate. See SSL Proxying in the Help menu. 
 - Response Code: 200 Connection established

How to configure the certificate in my app?

Regards,