Easiest way is prob to use the Strike API. If you wanna go the self-custodial route, I’d use LNbits. I think nostr:npub15klkdfx9sh3y096a5jf895rcvkmkzvly2fm9dgxq6huqhp9576jsav4m73 gives you a free LNbits server with a node. I know they used to give you one, but not sure if they still do.