Get Tailscale ip when using userspace networking mode


I have a caddy server + Tailscale running on AWS Fargate. Sadly currently I don’t get the Tailscale IP address this way. I tried to use caddy with the http proxy (need to use userspace networking) because I would assume I can get the IP header if I use the proxy but without any luck setting up caddy this way. Any idea how I can get the Tailscale IP address as a header?

Thank you!