This guide applies to the following error for Moz that happens when trying to query for "Domain to Page" results:
Query failed: Data fetch failed: 403 403 This account is not authorized to call this endpoint. For information about upgrading, please see http://moz.com/products/api
The error means that the account you are using to access the data has not been authorized to see the "Domain to Page" results. This most commonly happens if trying to use the default free limited access from Supermetrics.
This is a feature you normally have to pay extra for from Moz, so contact them to set up your API account (or upgrade it if you have one already). Instructions for how to use your own API for the request are here: How can I fetch Moz data using my own credentials?