Hey, On my Umbrel it includes Bitcoin Knots in the suggestions when asked if you want to setup Lightning - it doesn't require Core. A few things to look into: Did you already switch over to Knots? Is your Umbrel up to date?
Discussion
Umbrel up to date. Currently the lightning ⚡ node is still connected to Core. I've added Knots, waiting until indexing is finished.
I guess that I simply need to point to knots from the umbrel app shop. While preserving all channels and settings on my lightning. Right?
Excellent ⚡️ I didn't have to switch over from Core so I don't have direct experience and I am not 100% sure, but given what I've seen in my setup, once your Knots is synced up you should have it as an option for Lightning. I say this because when I select to install other Lightning apps it only shows Knots as a dependency (not Core). I would strongly recommend making a backup of everything before moving over either way, just in case 🙏🏼