There is a keepass app in Nextcloud to access your keepass database using a web browser (keeweb), keepassXC has a client for Linux, Mac and windows (and all of them work great) and there are many apps for iOS and android.
I use the free version of Strongbox with WebDAV and I haven’t had any problems.
You can just backup the keepass database file and you can also have several databases. Each database has its own password.
I’m using this with Nextcloud through WebDAV.
There is a keepass app in Nextcloud to access your keepass database using a web browser (keeweb), keepassXC has a client for Linux, Mac and windows (and all of them work great) and there are many apps for iOS and android.
I use the free version of Strongbox with WebDAV and I haven’t had any problems.
You can just backup the keepass database file and you can also have several databases. Each database has its own password.