There are multiple implementations out there. You can also run Albys implementation on your own node without connecting it to their server. For example there's an umbrel app that directly uses the node's lnd in their community appstore. The docker can be run on other systems as well with a little configuration 🤙. There's also implementations out there for c-lightning and LNbits.

https://github.com/getAlby/umbrel-community-app-store