There is no official government medical cannabis card in the UK. Access starts...

https://fast-wiki.win/index.php/Is_a_Medical_Cannabis_Card_Mandatory_in_the_UK%3F_Understanding_Your_Legal_Pathway

There is no official government medical cannabis card in the UK. Access starts with a specialist consultation and a review of your medical records to obtain a prescription. While not mandatory, some patients choose an optional card as proof of lawful use.