A LOT OF TIMES IF YOU TOUCH THE QR CODE, IT COPIES THE ⚡️ ADDRESS AUTOMATICALLY. THEN JUST PASTE THAT INTO NOTE HERE ON NOSTR. FROM THERE EVERYTHING IS BUILT IN. 
TRY POSTING ONE.
IMO THIS IS THE FUTURE FOR STANDS LIKE YOURS. SO EASY AND IM GUESSING ANY VISITORS SATURDAY WILL BE ABLE TO ZAP AN INVOICE.