Joinmarket. nostr:npub1rxysxnjkhrmqd3ey73dp9n5y5yvyzcs64acc9g0k2epcpwwyya4spvhnp8 has a great video on it 

https://m.youtube.com/watch?v=FbyjG2upGO8&pp=ygUKSmFtIG1hcmtldA%3D%3D