in lib/facebook_ads/ad_objects/server_side/util.rb [196:211]
def self.normalize_phone(phone)
normalized_phone = phone.gsub(PHONE_NUMBER_IGNORE_CHAR_SET, '')
if(is_international_number?(normalized_phone))
normalized_phone = normalized_phone.gsub(PHONE_NUMBER_DROP_PREFIX_ZEROS, '')
end
if normalized_phone.length < 7 || normalized_phone.length > 15
return nil;
end
return normalized_phone
end