No Mapping Rule matched

[cjing1]

Hi, I am trying to run the code with the demo image on Jupyter Notebook, but receive the following error:
No Mapping Rule matched

Did I not insert the image in the right way?

import requests

# I put my own id and key here
headers = {
    "app_id": " ",
    "app_key": " "
}

payload = '{"image":" https://media.kairos.com/kairos-elizabeth.jpg "}'

url = "https://api.kairos.com"

# make request
r = requests.post(url, data=payload, headers=headers)
print(r.content)