This is a bit of a crawling horror. If you're like me and use a different email address for every website you create an account on (so you can ditch the leakers) you won't ever be able to verify your age.
verifymy.io/age-verification-a…

I wonder whether the "online fingerprint" they talk about is entirely in accordance with the data protection policies of other sites I've provided data.

I also wonder whether it's discrimination against trans people on the grounds of gender reassignment, since we are more likely to have changed our name and email address, and may thus not be able to prove our age.

Email address age estimation FAQs - Verifymy

FAQs on email age estimation cover its process, privacy protection, certification, accuracy, and differences from age verification methods.

^{Verifymy Limited}