so i'm reading the Ofcom's guidance to do age gating, and would it be legal to have every user, before they log in, send in a photo of cigarettes or a beer next to like a post-it with their username and the date?

i feel this meets their 4 criteria
https://www.ofcom.org.uk/online-safety/illegal-and-harmful-content/age-assurance

for small, low-volume forums: this is an easily done manual check; it reveals little about the user except their general location on a national level and a small bit of handwriting; and it remains relatively pseudonymous

its criticisms apply to any other system such as credit card or ID scanning