There’s no official UK government cannabis card. Access is prescription-first...

https://sergioklwv602.bearsfanteamshop.com/how-to-avoid-wasting-time-when-booking-a-uk-medical-cannabis-consultation

There’s no official UK government cannabis card. Access is prescription-first via a specialist consultant after reviewing your medical records. If prescribed, you can opt for a private clinic card as optional proof of lawful use for police or employers.