https://www.aliexpress.com/item/NTAG215-NFC-TAG-NFC-Forum-Type-2-Tag-All-NFC-Phone-Available-NFC-Adhesive-Labels-Dia/32315909847.html This is the one I bought. Seems to be the only one on there too apart from some credit card style ones. It's not hard to find.
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The Real Jdbye
Boogieboo6
I saw those. I thought they were a lot cheaper though. Maybe they used to be. Then I ended up finding a user here that made 216 cards work like 215's and then I tried to find out how to do that myself, and then I gave up.