In 2018, the UK amended the Misuse of Drugs Regulations 2001—not the 1971...

https://www.blaze-bookmarks.win/since-2018-uk-cannabis-law-allows-specialist-doctors-to-prescribe-certain

In 2018, the UK amended the Misuse of Drugs Regulations 2001—not the 1971 Act—to allow specialist doctors to prescribe cannabis-based medicines like Sativex and Epidyolex. Cannabis remains a Class B drug, with recreational use still illegal