how to check if a phone number is valid whatsapp number in PHP?

so I have a text field that will be used as a view to get phone number from user, say if the phone number is +25678****** , I want to check if this number is a valid whatsapp number or not,i want to restrict the user to input fake whatsapp number, how to do that ?

I have searched every where on google but failed to get a solution