Not OP but regularly access my home network remotely. I have an Asus RT-AX86U which has a lot of features in the stock firmware, including OpenVPN configuration. If I need "LAN" access to my home network, I will open the OpenVPN client and then it will just work, this is useful to access things like local samba shares or SSH into my Linux machines (I was dissatisfied with the log spam of having an open SSH port even with fail2ban and router level protections).
If you have an always running server and only need access via a browser, forwarding port 80/443 to a reverse proxy works well. Dynamic DNS can be used if you don't have a static IP address. Alternatively, if you are more security conscious and don't mind the reliance on CloudFlare, you can use CloudFlare tunnel which won't expose ports from you local network at all. It can also be combined with a third party authentication mechanism.
Usually some kind of string search works. If it's frontend then search a string that's on the feature. If it's backend search a string for table name, http error messages, anything like that.
https://en.wikipedia.org/wiki/Microdistrict