If age verification has to be a thing (which isn't necessarily clear), then it should be up to the client to provide age indication to the server. It could be

If age verification has to be a thing (which isn't necessarily clear), then it should be up to the client to provide age indication to the server. It could be through a header, or something like this: https://developer.chrome.com/blog/digital-credentials-api-origin-trial https://developer.chrome.com/blog/digital-credentials-api-or... However, I have the feeling that none of these solutions will get wide enough buy in and adoption to be a viable solution to website owners.