Thanks Corndo™️
“Liquid Bitcoin (L-BTC) is a special type of asset on the Liquid sidechain, with a supply that is verifiably backed 1-to-1 with bitcoins (BTC) held by the Liquid Federation on the Bitcoin mainchain.”
https://help.blockstream.com/hc/en-us/articles/900001408623-How-does-Liquid-Bitcoin-L-BTC-work-
Discussion
You can easily swap them back to Lightning using https://boltz.exchange 🤙