How to send verification code to facebook inbox

I want to verify the users who sign up on my website by sending a verification code to their facebook/linkedin inbox, just like verifying through email. Is that possible with just a little bit of php code as is needed to send an email or do i have to go through Oauth ? Thanks

The easiest way to go about it would be to request the users Facebook email address which they can create via their account settings, if they don’t have a facebook email then you can request they create one before they can submit the form.

Thanks for the reply. But how would i ensure that the user is entering their Facebook email address and not any email address?

An easy way would be to ensure the end of the string is @facebook.com, if the string doesn’t match then force an error upon them.

you have to send a token request to their account if they accept you can grab their facebook email address. (from what i been reading)