SlotSet is returning None

first i am asking for country then setting the value of slot using SlotSet but it returns Null for first time but when i ask again it returns correct value

class CoronaStatus(FormAction):

def name(self) -> Text:

	return "corona_status"



@staticmethod
def required_slots(tracker: Tracker) -> List[Text]:
	"""A list of required slots that the form has to fill"""

	return ["country"]


def submit(
	self,
	dispatcher: CollectingDispatcher,
	tracker: Tracker,
	domain: Dict[Text, Any],
) -> List[Dict]:

	country = tracker.get_slot("country");
	dispatcher.utter_message(template="utter_total_patients")
	return [SlotSet("total_patients", "10000")]