Authorization using setting 'token_refresh_cmd' not working

Description

I tried to use Authorization with JWT. Therefore, my settings.json file looks like:

{
  "per_resource_settings": {},
  "max_combinations": 20,
  "authentication": {
    "token": {
      "token_refresh_cmd": "python3 getNewToken.py",
      "token_refresh_interval": 60
    }
  }
}

In the documentation, there is not really specified how the file getNewToken should look like. Currently, this file calls my POST /login endpoint, which returns the valid JWT. Then, the script prints this out. The script itself is working. But I think, I should need to return the JWT in some other format?

import json
import requests

# Function to get the token from the login endpoint
def get_token():
    url = "http://localhost:3000/login"
    # Replace with your actual login credentials if required
    login_data = {
        "username": "john_doe",
        "password": "password1234"
    }
    response = requests.post(url, data=login_data)
    if response.status_code == 200 or response.status_code == 201:
        # Assuming the token is in the 'token' field of the JSON response
        return response.json().get("access_token")
    else:
        print(f"Failed to get token: {response.status_code} - {response.text}")
        return None

# Get the token from the login endpoint
token = get_token()
if token:
    print(f"Authorization: Bearer {token}")
else:
    print("Could not retrieve the token.")

Steps to reproduce

All files are mentioned in my Description

Expected results

I expect everything to work and RESTler takes the correct Authorization header

Actual results

Authentication failed when refreshing token:

Using Token authentication method: 
TokenAuthMethod.CMD 
 with error unterminated string literal (detected at line 1) (<unknown>, line 1)

Authentication failed when refreshing token:

Using Token authentication method: 
TokenAuthMethod.CMD 
 with error unterminated string literal (detected at line 1) (<unknown>, line 1)

Authentication failed when refreshing token:

Using Token authentication method: 
TokenAuthMethod.CMD 
 with error unterminated string literal (detected at line 1) (<unknown>, line 1)

Authentication failed when refreshing token:

Using Token authentication method: 
TokenAuthMethod.CMD 
 with error unterminated string literal (detected at line 1) (<unknown>, line 1)

Authentication failed when refreshing token:

Using Token authentication method: 
TokenAuthMethod.CMD 
 with error unterminated string literal (detected at line 1) (<unknown>, line 1)
2024-06-10 14:50:57.390: Generation: 1 
2024-06-10 14:50:57.640: Terminating garbage collection. Waiting for max 300 seconds. 
Done.

Environment details

No response

microsoft / restler-fuzzer