We have a private app attempting to use the InventoryLevels endpoint to set available quantities. We can send GET requests to /admin/inventory_levels.json and retrieve inventory but attempting to send POST requests to /admin/inventory_levels/set.json appears to redirect us to a login page (note I've masked private info here, we clearly aren't trying to send <user>:<password> as part of the URL or update <item id>):
POST /admin/inventory_levels/set.json HTTP/1.1
"inventory_item_id": <item id>,
"location_id": <location id>,
We receive back an HTTP 200 with an html page asking us to login.
The x-request-id →19fa49f9-b031-43a7-aa58-6b93db4fc8a2
Is there something in Shopify we need to enable to use this endpoint?