Tim Streater wrote:

In the US you cannot even buy a mains plug, strickly speaking.

Home depot don't seem shy about selling them ...

https://www.homedepot.com/b/Electrical-Wiring-Devices-Light-Controls-Electrical-Plugs-Connectors/AC-WORKS/Eaton/GE/Legrand-Pass-and-Seymour/N-5yc1vZc336ZloZwcZ384Zh5oZhho?NCNI-5&experienceName=default&storeSelection=2408,2414, 2409,2407,2404