Vaultwarden is simpler to selfhost implementation of Bitwarden server fully compatible with it's apps.
ArchLinux have the server in official repos.
For Debian (.deb) I have found this unofficial repo: https://github.com/gvtulder/vaultwarden-deb Be mindful it suggests stupid installation method by downloading and executing the install.sh script directly, you may want to read it yourself before install.
For .rpm I haven't find any repositories that are actively maintained, but you may have more luck.