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, 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)