UK cannabis laws were adjusted in 2018 through the Misuse of Drugs Regulations...

https://www.acid-bookmarks.win/since-2018-uk-law-permits-specialist-doctors-to-prescribe-cannabis-based

UK cannabis laws were adjusted in 2018 through the Misuse of Drugs Regulations 2001, not the Misuse of Drugs Act 1971. This change made some cannabis-based medicines, like Sativex and Epidyolex, available on prescription but only from specialist doctors