They want evidence from your GP that you don't drink, this is usually a date of last drink logged with your GP and backed up with regular LFT testing with results within the normal parameters. I don't think it's too new, it was what I had to do in 2019 and what members on here report going back a few years before my medical licence was issued.
I'm sure you had your GP's support in the first place and would have told them when you stopped drinking, that should still be on file so just make an appointment to see them, get an LFT and send their recommendation plus that LFT result as evidence with your renewal and hope for the best.