If you have a domain on cloudflare you can make it point to your public ip using something like this https://github.com/timothymiller/cloudflare-ddns

Also some routers, like tp-link, have a ddns feature where they provide you a domain that points to your public ip

Benn Jordan has a video on that, quite interesting

https://www.youtube.com/watch?v=eRPeU1DYOWA&t=5

Is Eternity still maintained? On fdroid the last version is from 2 years ago.