How is registration / authorization through the social. networks using oAuth2 if one of the social networks does not give email / phone?

Question

OAuth

I am making a website on Laravel, for authorization via oAuth2 I use the Socialite package with the necessary providers.
The following questions arose:
1) How to register / authorize a user on the site, for example, through social networks. Facebook network, if he has only a phone number (without email) in his account, and Facebook, does not return the user's phone number?
2) for example, it is possible to go to the Odnoklassniki website through Facebook. But then the user turns out to have neither a phone nor an email, respectively, he will not be able to log in to Odnoklassniki without Facebook (if he does not specify a login and password there)!?
3) Did I understand correctly that most sites (facebook, vk, google, ...) do not return the user's phone number?

Answer 1

1) Why do you need a soap/phone to register? That's right, there is no need - there is a social network ID, there is a driver name, that's enough. But if they are needed for the further use of your application, then require the user to specify them additionally during the registration process / after it.
2) Ask Odnoklassniki.
3) Yes. Many do not even give away soap - Odnoklassniki only with additional gestures, Twitter does not at all. Upd: In the comments, they suggest that now Twitter gives back if it is good to ask about it.