403 Error

Any PUT or POST API responses have a status of 403 for me. GET requests work fine, so I suspect a permissions error with my token even though I have write access to the project. Here's some example code. Has anyone else run into this issue?

response = requests.put(
    f'https://radformation.matrixreq.com/rest/1/RAD_PROJECT/item/XTC-61',
    headers={'Authorization': 'Token ' + TOKEN},
    data={
        'itemProperties': {'Notes': 'test'},
        'onlyThoseFields': 1,
    }
)