There is no government-issued medical cannabis card in the UK. Access requires...

https://highstylife.com/how-long-does-the-medical-cannabis-approval-process-take-in-the-uk/

There is no government-issued medical cannabis card in the UK. Access requires a specialist consultation and your medical records. With a prescription, you can purchase an optional card as proof of lawful use, though this is not a legal requirement.