Problem in invoking HTTP API to execute action from Postman app

I am trying to execute an action using HTTP API from the Postman app. I am storing my tracker using the PostgreSQL tracker store.

Rasa version used: 1.1.8

POST API: http://127.0.0.1:5005/conversations/myid/execute

Header: Content-Type=“application/json”

JSON body:  {
  "name": "action_http"
}

I get the following error in terminal, while invoking execute action POST api from Postman app:

2019-11-18 11:10:28 DEBUG    rasa.core.actions.action  - Calling action endpoint to run action 'action_http'.
2019-11-18 11:10:29 ERROR    rasa.core.processor  - Encountered an exception while running action 'action_http'. Bot will continue, but the actions events ar
e lost. Please check the logs of your action server for more information.
2019-11-18 11:10:29 DEBUG    rasa.core.processor  -
Traceback (most recent call last):
  File "d:\workspace\pyanalytics\rasapoc\venv\lib\site-packages\rasa\core\processor.py", line 445, in _run_action
    events = await action.run(output_channel, nlg, tracker, self.domain)
  File "C:\Python36\lib\asyncio\coroutines.py", line 129, in throw
    return self.gen.throw(type, value, traceback)
  File "d:\workspace\pyanalytics\rasapoc\venv\lib\site-packages\rasa\core\actions\action.py", line 399, in run
    json=json_body, method="post", timeout=DEFAULT_REQUEST_TIMEOUT
  File "C:\Python36\lib\asyncio\coroutines.py", line 129, in throw
    return self.gen.throw(type, value, traceback)
  File "d:\workspace\pyanalytics\rasapoc\venv\lib\site-packages\rasa\utils\endpoints.py", line 144, in request
    **kwargs
  File "C:\Python36\lib\asyncio\coroutines.py", line 129, in throw
    return self.gen.throw(type, value, traceback)
  File "d:\workspace\pyanalytics\rasapoc\venv\lib\site-packages\aiohttp\client.py", line 1005, in __aenter__
    self._resp = await self._coro
  File "C:\Python36\lib\asyncio\coroutines.py", line 129, in throw
    return self.gen.throw(type, value, traceback)
  File "d:\workspace\pyanalytics\rasapoc\venv\lib\site-packages\aiohttp\client.py", line 476, in _request
    timeout=real_timeout
  File "C:\Python36\lib\asyncio\coroutines.py", line 129, in throw
    return self.gen.throw(type, value, traceback)
  File "d:\workspace\pyanalytics\rasapoc\venv\lib\site-packages\aiohttp\connector.py", line 522, in connect
    proto = await self._create_connection(req, traces, timeout)
  File "C:\Python36\lib\asyncio\coroutines.py", line 129, in throw
    return self.gen.throw(type, value, traceback)
  File "d:\workspace\pyanalytics\rasapoc\venv\lib\site-packages\aiohttp\connector.py", line 854, in _create_connection
    req, traces, timeout)
  File "C:\Python36\lib\asyncio\coroutines.py", line 129, in throw
    return self.gen.throw(type, value, traceback)
  File "d:\workspace\pyanalytics\rasapoc\venv\lib\site-packages\aiohttp\connector.py", line 974, in _create_direct_connection
    req=req, client_error=client_error)
  File "C:\Python36\lib\asyncio\coroutines.py", line 129, in throw
    return self.gen.throw(type, value, traceback)
  File "d:\workspace\pyanalytics\rasapoc\venv\lib\site-packages\aiohttp\connector.py", line 924, in _wrap_create_connection
    await self._loop.create_connection(*args, **kwargs))
  File "C:\Python36\lib\asyncio\base_events.py", line 764, in create_connection
    yield from self.sock_connect(sock, address)
  File "C:\Python36\lib\asyncio\selector_events.py", line 450, in sock_connect
    return (yield from fut)

BTW this works fine when I try to invoke this HTTP API from javascript. Has anyone ever faced such issue?