code: def phonenumber_validation(data):
      
      from phonenumber_field.phonenumber import to_python
      phone_number = to_python(data)
      if not phone_number:
          return data
      elif not phone_number.country_code:
          raise serializers.ValidationError(_("Phone number needs to include valid country code (E.g +37255555555)."))
      elif not phone_number.is_valid():
          raise serializers.ValidationError(_('The phone number entered is not valid.'))
  
      return data
docs: Validates phonenumber
  
      Similar to phonenumber_field.validators.validate_international_phonenumber() but uses a different message if the
      country prefix is absent.