Did you try BitWarden? I haven't yet, but it's supposed to be basically a FOSS alternative to LastPass / 1Password.
So I can't habe autofill, automatic saving of new/changed passwords and password creation and also use the same vault for the mobile app (Android). The mobile app can access the self hosted vault without any issue.
I would love to fully migrate to self hosted bitwarden, but the browser extension irks me. Maybe it is possible and I am just too dumb to find the solution.
I could only enter email and password yesterday.
There is a small cog in the top left side where you can change the URL to use when you login, in case you simply overlooked it.
Top left here: https://imgur.com/xCgrot0
If you click on that, the "Server URL" field is where you want to put your private instance: https://imgur.com/Gua3jSb