Stick an NFC sticker inside the ring and write this link to it. The QR already carries it:

https://sliplio.citisoftsolutions.com/receipt?d=eyJzdG9yZSI6IkxhbnRlcm4gQ29mZmVlIiwiYWRkcmVzcyI6IjExMiBIYXJib3VyIFJvYWQgwrcgVW5pdCA0IiwibG9nbyI6IkwiLCJudW1iZXIiOiJJTlYtOTA0MTIiLCJjdXJyZW5jeSI6IiQiLCJ0YXhSYXRlIjowLjA4NSwiY2FyZCI6IlZpc2EgwrfCt8K3wrcgNDI5MSIsIm5vdGUiOiJUaGFua3Mg4oCUIHNlZSB5b3Ugc29vbi4iLCJpdGVtcyI6W3sibmFtZSI6IkNhcHB1Y2Npbm8iLCJxdHkiOjIsInByaWNlIjo0LjJ9LHsibmFtZSI6IkJ1dHRlciBDcm9pc3NhbnQiLCJxdHkiOjEsInByaWNlIjozLjZ9LHsibmFtZSI6IkJsdWViZXJyeSBNdWZmaW4iLCJxdHkiOjIsInByaWNlIjozLjk1fV19

A 25 mm NTAG215 sticker fits the ring nicely. Write it from the Build a receipt page, or with the free NFC Tools app.