You want these:

Others can work but I think only these require no merchant involvement.

That one works for me. I have also been able to use the phone app, but not the other various payment terminal styles.

This is great news, as I'm pretty sure that's what they have. Combined with the answer from Bullish Bitcoiner, it sounds like the problem was my expectations (a QR code). And it looks like Zeus might be able to do the NFC thingy if I give it permission. This is looking optimistic. Adversarial integration. 😈

I have had similar experiences to your original posts with a different type of front facing terminal. I love NFC. It's the easiest way to connect my wallet to cool stuff.

I get that, but really like this crew. It's mostly volunteer run, prices quite a bit lower than Amazon, unbelieveably good service, and I want to support a local brick & mortar shop. So it's hard for me to take a 🖕attitude for this particular establishment. There's just one or maybe two people there who probably heard the altcoin-financed narritive from 5 years ago and never got any updated info after that got debunked. Or they conflate bitcoin and crypto. I don't really know what their objection is and I don't want to bring it up, as it'll just be an argument and I don't think anyone would change their mind at the end of it. In any case, I want to build my case, slowly and carefully. Use it for a while (if they didn't explictly disable it) without saying a word. If they catch it, then we can have a conservation about how I use bitcoin because I'm an environmentalist. Otherwise, I'll just wait for it to come up naturally. Plus knowing will help me with other businesses that use Square. That way I can test it out in practice before I attempt a live demo.