Testing flask end point with import requests

Question

I was learning flask or trying to along with mongodb and things were mostly going okay. Though I am having a heck of a time figuring out what object is coming back to my little test_api.py of my api.py flask endpoint.

api.py

#uses mongo engine

#simple data structure
class SimpleDocument(db.Document):
    docName = db.StringField()
    docAction = db.StringField()
    def to_json(self):
        return {"id": self.id,
                "name":self.docName,
                "action":self.docAction}


@app.route('/document/', methods=["POST"])
def add_simpledocument():
    body  = request.get_json()
    simpledoc= SimpleDoc(**body).save()
    print(simpledoc.to_json())
    return simpledoc.to_json(), 201 # i would like to return the object so I have the ID of the object just created too...

now in my test_api.py I have:

def test_addSimpleDoc():
    url = 'http://localhost:5000/document/'    
    headers = {'Content-Type': 'application/json'}
    payload = {'name':"Simple Name Test", 'action':'What the doc does'}
    resp=requests.post(url, headers=headers, data=json.dumps(payload,indent=4))    
    print(resp.json["id"])   
    #cannot figure out how to get the id of the object I just created...

Fials with a print(resp.json["id"]) method is not subscriptable. Clearly I have no idea what type of object is coming back to me.