For more robust merchant POS features, you could use nostr:npub155m2k8ml8sqn8w4dhh689vdv0t2twa8dgvkpnzfggxf4wfughjsq2cdcvg. There’s even a Blink plugin recently released to receive payments directly to your Blink wallet https://www.blink.sv/blog/introducing-the-blink-plugin-for-btcpay-server