Here is the explanation of the NIM to BTC LN bridge, including some details of how it works under the hood. If you wanted to get hands-on, you could get your hands on some NIM and try sending it to your Alby wallet. DM me and I will send you some NIM to your Nimiq Pay app! https://www.nimiq.com/blog/pay-with-nim-everywhere-lightning-network-is-accepted/