LinuxGuy I want to know if Graphene OS is a US company or a Canadian company?
GrapheneOS is not a company, it's an open source project with devs all around the world. With that said, the project organized GrapheneOS Foundation nonprofit in Canada to accept donations and to pay devs for the work.
LinuxGuy I pay contact-less via Smartwatch or Smartphone.
You can use a standalone device to use tap-to-pay. Some community members had success with Garmin smartwatch. Please use the forum search function to find related discussions.
LinuxGuy In general would that be possible, right? NFC should work.
NFC works with GrapheneOS, it's Google Pay that chooses not to work with GrapheneOS, so you can find a bank app which has it's own implementation of tap-to-pay functionality in their app and it will work with GrapheneOS via NFC.
The cheapest and easiest option would be a credit card under a phone case (or in a phone case with CC pocket). I mean you'll still be tapping your phone to pay, just nothing happens under the hood software wise.