There is no UK government medical cannabis card. Access requires a specialist...

https://www.herald-dispatch.com/sponsored/how-to-get-a-medical-cannabis-card-in-the-uk-step-by-step/article_a7f9fcb2-55db-40ff-857f-db6b98c92a97.html

There is no UK government medical cannabis card. Access requires a specialist consultation and medical record review for a prescription. While optional, a clinic-issued card serves as helpful proof of lawful use to show authorities or employers if asked.