No response needed. Relay keeps track of the invoice and grants access as soon as it's paid. People can fake payments on Nostr, but they cannot do it on lightning. 

Not draft yet. I need to do some final tests with the invoice db nostr:npub18kzz4lkdtc5n729kvfunxuz287uvu9f64ywhjz43ra482t2y5sks0mx5sz has, but it seems to be working.