I would look into Tailscale based on your responses here. I don’t know what your use case is exactly but you set TS up on your server and then again on your phone/laptop and you can connect them through the vpn directly. No extra exposed ports or making a domain or whatnot.

If you want other people to access the server they will need to make a TS account and you can authorize them.

I did this with all the stupid moth memes. I want to see less of this so I downvoted them all. (Along with blocking a few communities)