Two-factor login for user

I have a collegue with an Adobe Sign subscription and he would like to set up two-factor verification.

He has his Adobe account (which he has an email, password and two-factor verification).

I was told by Adobe that this would pull through to the Adobe Sign account and he woud have the two-factor verification on this too, but he doesn't.

I've looked all through the user settings and I can't see an option to do this, can anybody help?

I should also note: he has the same email for the two accounts but the password is different for both if that helps.

Thanks

Charley