In 2018, UK cannabis law changed through updates to the Misuse of Drugs...

https://bizzmarkblog.com/is-cannabis-decriminalised-anywhere-in-the-uk/

In 2018, UK cannabis law changed through updates to the Misuse of Drugs Regulations 2001, not the Misuse of Drugs Act 1971. This allowed specialist doctors to prescribe cannabis-based medicines like Sativex and Epidyolex under Schedule 2 rules