I'm using the code from https://developer.themoviedb.org/v4/reference/list-add-items, just adding the listId. The first request, for getting the list, works. But the second one, to add items to it returns status_code:34

I'm using the access token from https://developer.themoviedb.org/v4/reference/auth-create-access-token on my request. I tried creating a list with the same token, and that works

url = "https://api.themoviedb.org/4/list/8271848"

headers = {
    "accept": "application/json",
    "Authorization": "Bearer TOKEN"
}

response = requests.get(url, headers=headers)

print(response.text)

url = "https://api.themoviedb.org/4/8271848/items"

payload = { "items": [
        {
            "media_type": "movie",
            "media_id": 820609
        },
        {
            "media_type": "tv",
            "media_id": 72710
        }
    ] }
headers = {
    "accept": "application/json",
    "content-type": "application/json",
    "Authorization": "Bearer TOKEN"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

The result is below:

{"average_rating":0,"backdrop_path":null,"comments":[],"created_by":{"gravatar_hash":"81718ca16ada2381f0b308e81fce4da2","id":"5fdfe400764841003f6f9627","name":"","username":"falconsensei"},"description":"","id":8271848,"iso_3166_1":"US","iso_639_1":"en","name":"Old Stuff","object_ids":[],"page":1,"poster_path":null,"public":true,"results":[],"revenue":0,"runtime":0,"sort_by":"original_order.asc","total_pages":1,"total_results":0}
{"status_code":34,"status_message":"The resource you requested could not be found.","success":false}