Directory of Square merchants:

https://giveandgetlocal.com/

And how to enable Bitcoin:

https://squareup.com/help/us/en/article/8554-accept-bitcoin-payments-with-square-alpha

Don’t forget to add them to nostr:npub1864jglrrhv6alguwql9pqtmd5296nww5dpcewapmmcazk8vq4mks0tt2tq