I created a “mobile app” authentication and a “web app” authentication, both at the account level (not at the product level). I then attempted to look up data_usage for one of my Particle SIMs. The device with this SIM is associated with a product and my authentications are the account level since I have multiple products (one auth to check all sims/products).
You need to use an actual user token (not oAuth or API user) in order to access multiple products in the free tier. Once you are growth or enterprise you can use a organization-level API user for that purpose.
I’m okay focusing on a single product and not worrying about a “meta user” or “super user” for the entire sandbox. That said, creating a user authentication with full permissions in the product is not allowing the data_usage API call to work for sims that are also in the same product. Guess I better ask, what is meant by “actual user token”?