Missing Authentication Token for C3.ai COVID-19 Data Lake

I’m using the C3.ai COVID-19 Data Lake in Python, but I get missing authentication token errors. What am I doing wrong? An example:

import requests
r = requests.get(
    "https://api.c3.ai/covid/api/1/therapeuticasset/fetch", 
    json = {
        "spec" : {
            "filter" : "therapyType == 'Vaccine'"
        }
    },
    headers = {'Accept' : 'application/json'}
)
r.json()

I get back:

{'message': 'Missing Authentication Token'}

As per API documentation about TherapeuticAsset, make sure to submit the fetch as a POST request rather than a GET:

import requests

r = requests.post(
    "https://api.c3.ai/covid/api/1/therapeuticasset/fetch", 
    json = {
        "spec" : {
            "filter" : "therapyType == 'Vaccine'"
        }
    },
    headers = {
        'Accept' : 'application/json',
        'Content-Type': 'application/json'
    }
)

r.json()

Using POST requests is a requirement for all the supported metrics in the C3.ai COVID-19 API.