I am trying to obtain access to Marketplace Insights API for completed items (5000 call limit) however premium support suggested I go through EPN. I cant register for EPN without providing a link to my app, though I cant develop the app without the API access through the EPN. Is anyone able to provide some insight to this? Is it possible to register for EPN without a developed app? Or is it possible to gain access to API on sold items before registering for EPN and going through Marketplace Insights?
Hmm, that's something of a conundrum. You should be able to access the Sandbox for Marketplace Insights (MI), which contains a predefined set of sample listings. Perhaps create a quick workup/demo of an app that uses MI/Sandbox, then apply for ePN? I'm not sure what the rules are these days for applying anew to ePN. There may be other ways to get admitted besides having an app already made.
Hmm, that's strange. You should have Sandbox access right away. Are you following all the steps for generating a refresh token, specifying scopes, etc? Have you used the API Explorer in your Dev account to call Sandbox APIs successfully? I haven't tinkered with the Buy APIs in a couple years. You should ask for help over in the Buy API sub-forum, and make sure you're getting an active token properly.