You tie it cryptographically to their phone with keys in the phone's hardware security module. This doesn't stop sharing of ID but it makes it much more inconvenient.
Why would you invite a technology that by definition makes websites accessible only via phones? These social media age verification laws are inevitably going to hit sites you use, too.
And I access the website from my computer how?
Why would you invite a technology that by definition makes websites accessible only via phones? These social media age verification laws are inevitably going to hit sites you use, too.