Syntax error in validation method (self)

I have the FormAction code:

lass ActionRegistration(FormAction):

def name(self) -> Text:
    return "registration_form"

@staticmethod
def required_slots(tracker: Tracker)  -> List[Text]:
    print("required_slots(tracker: Tracker)")
    return ["name", "ps"]

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

    dispatcher.utter_message(text="We are validating your data")

    return []

@staticmethod
def ps_db() -> list[Text]:
    names_of_ps = ['lalapet', 'arundalpet', 'brodipet']
    return names_of_ps

def validate_ps(
    self,
    value: Text,
    dispatcher: CollectingDispatcher,
    tracker: Tracker,
    domain: Dict[Text, Any],
) -> Dict[Text, Any]:
    if value.lower() in self.ps_db:
        return {"ps":value}
    else:
        return {"ps":None}

I.m getting error as

File “C:\Users\Boyinapalli Sandeep\desktop\virt\comp\complaint\actions.py”, line 56 self, ^ SyntaxError: non-default argument follows default argument

I have copy pasted the function paramters from rasa tutorials.

the type annotation sohuld have a capital ‘L’, so

List[Text]