They handle all the lightning stuff on the back end and you don't have to worry about it. You just send them your sats and they issue you a shitcoin. basically.

So you're interoperable with the lightning network through their token. It's a great UX, but of course it's custodial so they can rugpull you
and they could also print tokens that weren't backed by Sats.

so it's a bank as the OP describes.

you can use anybody's mint because on the back end they're connected to all the other LN nodes. So if you trust that nostr:nprofile1qqsw9n8heusyq0el9f99tveg7r0rhcu9tznatuekxt764m78ymqu36cpz4mhxue69uhhyetvv9ujuat50phjummwv5hszymhwden5te0wahhgtn4w3ux7tn0dejj7qg4waehxw309an8yetwwvh82arcduhx7mn99uuwx66a guy, you can use his tokens.
or you and your buddies could spin up a mint.