You can selfhost bitwarden, there’s also vaultwarden, an open bitearden api implementation. You could host this on an internal-only server.
But you also can sync your single password file with a lot devices and use keepass, I just find that a bit annoying. You also cannot share some passwords with your relatives easily that way.
Mainly cuz it doesn’t store your passwords on someone else’s computer.
You can selfhost bitwarden, there’s also vaultwarden, an open bitearden api implementation. You could host this on an internal-only server. But you also can sync your single password file with a lot devices and use keepass, I just find that a bit annoying. You also cannot share some passwords with your relatives easily that way.