Authentication with Fast API Error failed, key \"message\" not found"

[53845714nF]

I have the following FastAPI App:

from os import getenv
from fastapi import FastAPI, Body, HTTPException
from ssl import create_default_context, Purpose
from gql import Client
from gql.transport.aiohttp import AIOHTTPTransport
from argon2.exceptions import VerifyMismatchError
from graph_ql import create_user, find_user_by_email
from utils import Password, generate_token, rehash_and_save_password_if_needed
from signup_types import SignupArgs, CreateUserOutput

url = getenv("HASURA_URL")

ssl_ctx = create_default_context(Purpose.CLIENT_AUTH)
ssl_ctx.load_verify_locations(cafile='conf/CA.pem')
transport = AIOHTTPTransport(url=url, ssl=ssl_ctx)
client = Client(transport=transport, fetch_schema_from_transport=True)


app = FastAPI()

@app.post("/signup", response_model=SignupArgs)
async def signup_handler(args: SignupArgs = Body(...))-> CreateUserOutput:
    hashed_password = Password.hash(args.password)
    user_response = create_user(args.name, args.email, hashed_password)
    
    if user_response.get("errors"):
        raise HTTPException(status_code=400, detail=user_response["errors"][0]["message"])
    else:
        user = user_response["data"]["insert_user_one"]
        return  CreateUserOutput(**user)

My Hasura Action:

I get the following Error:

{
  "errors": [
    {
      "message": "parsing Hasura.GraphQL.Execute.Action.Types.ActionWebhookErrorResponse(ActionWebhookErrorResponse) failed, key \"message\" not found",
      "extensions": {
        "path": "$",
        "code": "parse-failed",
        "internal": {
          "error": "unexpected response",
          "request": {
            "body": {
              "action": {
                "name": "Signup"
              },
              "input": {
                "email": "test3",
                "name": "test3",
                "password": "test3"
              },
              "request_query": "mutation MyMutation {\n  Signup(email: \"test3\", name: \"test3\", password: \"test3\") {\n    id\n  }\n}",
              "session_variables": {
                "x-hasura-role": "admin"
              }
            },
            "headers": [],
            "transformed_request": null,
            "url": "http://fast_jwt:8000/signup"
          },
          "response": {
            "body": {
              "detail": [
                {
                  "input": null,
                  "loc": [
                    "query",
                    "args"
                  ],
                  "msg": "Field required",
                  "type": "missing",
                  "url": "https://errors.pydantic.dev/2.4/v/missing"
                }
              ]
            },
            "headers": [
              {
                "name": "date",
                "value": "Wed, 25 Oct 2023 20:34:53 GMT"
              },
              {
                "name": "server",
                "value": "uvicorn"
              },
              {
                "name": "content-length",
                "value": "140"
              },
              {
                "name": "content-type",
                "value": "application/json"
              }
            ],
            "status": 422
          }
        }
      }
    }
  ]
}

What can I do?