Forbidden from using only incremental API calls?

Hi all - I'm our company's resident stats guy (admittedly not much of a coder) and I need to pull a bunch of our tickets from Zendesk along with any associated comments. I can do that just fine by searching for tickets between two dates and pulling each comment one-by-one, but that isn't quite as efficient as using incremental+sideloading to dump things. However, when I try any endpoint starting with /api/v2/incremental/, I get this error:

{"error": {"title": "Forbidden", "message": "You do not have access to this page. Please contact the account owner of this help desk for further help."}}

I cannot find any mention of extra required permissions in the API documentation, nor are there any other permissions we can see that I might need. What am I doing wrong here? Do we need a different plan for this?