Can it be self-hosted like vaultwarden?
Discussion
It's not like Vaultwarden, but sure. You can host the database file wherever you want.
I’ve used the same for almost as long. Just works. 👍🏼
It’s a simple database file you store locally so you are self-hosting by default.
You can synchronize the file between devices with your Nextcloud or syncthing. Keep in mind that you need to keep backups of that file!