Trouble forming a mutation schema for GraphQL with python and Flask

Question

I have been going round and round with GraphQL. I am using Flask and need to create a mutation to a GraphQL api. I have been trying to use Graphene but I am having trouble forming my schema correctly.

I am trying to follow Eradash's response but not sure how to form the schema. My original working (hard coded) schema is in mutation.py and my updated is named updated_mutation.py. Thank you for any guidance.

mutation.py

def run_query(query): # A simple function to use requests.post to make the API call. Note the json= section.
    request = requests.post('https:/xxxxx.com/api/', json={'query': query}, headers=headers)
    if request.status_code == 200:
        print(request.json())
    else:
        raise Exception("Query failed to run by returning code of {}. {}".format(request.status_code, query))


# The GraphQL query (with a few aditional bits included) itself defined as a multi-line string.
parameter = "Meeting Test"

query = """mutation {
  createMeeting(
    input: {
      meetingName: "Meeting on Calendar - API"
      scheduledDateTime: "Thu Jul 30 2020 14:00:00 -0500"
      scheduledTimeZone: "CDT/UTC-05:00"
      endDateTime: "Thu Jul 30 2020 15:00:00 -0500"
      enableTwilio: 1
    }
  ) {
    message
    result
    status
  }
}
"""

result = run_query(query) # Execute the query

update_mutation.py

import requests

headers = {"apiToken": "your_token"}
def make_query(self, query, variables, url, headers):
    """
    Make query response
    """
    request = requests.post(url, json={'query': query, 'variables': variables}, headers=headers)
    if request.status_code == 200:
        return request.json()
    else:
        raise Exception("Query failed to run by returning code of {}. {}".format(request.status_code, query))

query = """
    mutation createMeeting{($meetingName:MeetingInput,
    $scheduledDateTime: starttime,
     $scheduledTimeZone: timezone,
     $endDateTime: endtime)
        }
        {
          message
          result
          status
    }
"""
variables = {
'meetingName': name,
'scheduledDateTime': starttime,
'scheduledTimeZone': timezone,
'endDateTime': endtime
}