Someone mentioned Vaultwarden and I didn't know it, a Rust implementation to run on our own server with less resources compared to the official implementation. But the other one also mentioned, KeepassXC, I confirm is really good. Just you would have to find your way to sync for usage across multiple devices. Maybe Proton Drive could be enough for that. On Linux at least, I think the way KeepassXC interacts with the browser is better than Bitwarden. In particular, I like the small icon displayed in forms to auto-complete passwords instead of doing it automatically.