Likely what you have seen on youtube is someone paying with a non-standardized payment system… something custom, like paying with bitcoin or venmo or a loyalty card type system… standard “tap and pay” use the EMV standard and there are no serious implants that can do that yet. We are working on VivoKey to try to enable EMV payments but it will be a long difficult road to get there.
Some people have simply removed a chip from a bank card and implanted that, but this is a temporary solution since those chips expire after a few years. It’s not a real commercial solution.