The easiest way to do this is through Tailscale. It is a super easy to set up Wireguard VPN Mesh that allows you to access your self-hosted services without exposing them to the public internet.
Note: while this way not directly answer OP's specific question, I believe they will get the outcome they are looking for: external access to self-hosted services
I find that using AI can sometimes help me get the ball rolling. Rather than having a blank page, I have some (sometimes shitty) code that I can start from. I have never used 100% of generated code in production.
The easiest way to do this is through Tailscale. It is a super easy to set up Wireguard VPN Mesh that allows you to access your self-hosted services without exposing them to the public internet.
https://tailscale.com/
Here is a great article to get you started: https://tailscale.com/kb/1017/install
They also have an awesome YouTube channel with great tutorials to help you get started. https://www.youtube.com/@Tailscale
Note: while this way not directly answer OP's specific question, I believe they will get the outcome they are looking for: external access to self-hosted services