Just delete “cash” from the app, and insert an option “another payment type as per mutual agreement”
After the Nostr/Plebstr zap fiasco, Apple has found a new low. Recommending people to use cash is "clearly reckless", as authors of peer to peer Bitcoin trading app nostr:npub1mftv2j67vayavkks8rqev3u8jjhefe86tf80msstfxvpunk9vmps6prkl3 have found out.
https://blog.vexl.it/apple-using-cash-is-clearly-reckless-77e2a519a3bc
PWA is the way:
https://juraj.bednar.io/en/blog-en/2023/08/01/goodbye-app-lets-move-from-the-centralized-stores/
Discussion
It allows different payment methods, but electronic fiat payments are reckless, so it does not recommend them.