Error in python API call - Jsondecodeerror

Question

I’m making this call in a Mailchimp API, but it’s returning an error in json that I don’t know how to solve, can help me??

My code:

import requests
import psycopg2


key = 'KEY'
url = 
'https://us17.api.mailchimp.com/3.0/ecommerce/stores/id_loja/carts? 
count=10000'
head = {'anystring':KEY}

r = requests.get(url, auth=('user',key))

info = r.json()

print(info)

Error that returns:

raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)