Rasa Interface: Tracker object is not JSON serializable

Rasa Open Source
1 
from typing import Any, Text, Dict, List
from rasa_sdk.events import SlotSet, EventType

from rasa_sdk import Action, Tracker
from rasa_sdk.executor import CollectingDispatcher


class ActionHelloWorld(Action):

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

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

        # date = tracker.get_slot("time")
        date = next(tracker.get_latest_entity_values("time"), None)
        dispatcher.utter_message("utter_ask_time", tracker, timer=date)

        return []

Getting following error for custom action for above code, any help would be appreciated

While executing rasa run actions-

Traceback (most recent call last):
  File "handle_request", line 83, in handle_request
    )
  File "/home/anushkas/.local/lib/python3.8/site-packages/rasa_sdk/endpoint.py", line 114, in webhook
    return response.json(result, status=200)
  File "/home/anushkas/.local/lib/python3.8/site-packages/sanic/response.py", line 217, in json
    dumps(body, **kwargs),
TypeError: <rasa_sdk.interfaces.Tracker object at 0x7f19400203d0> is not JSON serializable

In rasa shell-

Traceback (most recent call last):
  File "/home/anushkas/.local/lib/python3.8/site-packages/rasa/core/processor.py", line 874, in _run_action
    events = await action.run(
  File "/home/anushkas/.local/lib/python3.8/site-packages/rasa/core/actions/action.py", line 765, in run
    raise RasaException(
rasa.shared.exceptions.RasaException: Failed to execute custom action 'action_date'
2

having the same issue and showing error in connection to the webhook