I loved FFSend. When it died, I ended up standing up a GOKAPI server, as it was the closest alternative I could find at the time: https://github.com/Forceu/Gokapi

Definitely not as nice as FFSend though. I may have to give that fork a try instead.

Here’s the note taking and editors page of awesome-selfhosted. Looks like there are a few contenders in there. DailyTxT looks decent for your use case.

https://awesome-selfhosted.net/tags/note-taking--editors.html