Home Help - NAT user IP?

I have setup a personal Flared tunnel for a few of my home/local web apps. This is working great.

Very basic setup, though I have just setup Access portal with google auth (though don’t think this is relevant). This also is working great.

This basic config results in the users PAT/external IP being used, and some of my apps (properly) require their own authentication since it is seen as an external connection.

Is there a feature, where I can NAT these connections to a local network IP?

I am reading up on the tunnel private network options, but I am a little bit out of my depth here.