After having set up your server and having gained a decent amount of users (or covering a new geographic area), simply provide me the the details of your server here, preferrably in the json format: https://github.com/hrydgard/ppsspp/blob/master/assets/adhoc-servers.json
You can do this by posting in the discord or emailing [email protected].
If you don't have a hostname but just an ip, specifying ip as host is fine. However, I do recommend using a hostname in case your IP needs to change in the future.
Also consider adding support for status_data_json, see https://www.ppsspp.org/docs/multiplayer/adhoc-server-status/ . This will allow in-app display of current games.