You install this app on your own node instead of using the alby nwc website. It then will use your lnd.
Discussion
I run a slightly modified version that uses lnbits instead of lnd to have a separate zap wallet.
Please tell me more 🧐 I'm just starting out with Lnbits
This offers a selection between lnd and lnbits when creating a session. If you run lnbits on your umbrel you can simply add the admin key of the wallet you want to use and leave the host field empty. It's not an official version tho and just my playground.
https://github.com/believethehype/umbrelapps/tree/master/believethehype-wallet-connect