We have a pre-existing private app in our Shopify store that does some stuff, but we wanted to leverage this app to help inform Shopify of the inventory stock of items in our store.
We have setup a/fetch_stock.json endpoint in the private app receive a callback for products configured to have their inventory managed by the private app.
We have our callback_url set to our root url, (so we know the url Shopify should hit it root/fetch_stock.json).
We have tried toggling between the different inventory managers.
No matter what we do, we still have not seen any callback triggered within our private app. We have manually hit the endpoint through postman and verified that the endpoint works, and correctly logs activity when it is hit. We reached out to our customer support contact, and they gave up and pointed us to the forums.