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

https://www.slideserve.com/eogernrhbu/is-there-a-review-of-the-2018-medical-cannabis-change-happening-now

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