Amazon MCF and Buy with Prime

The app is currently unusable. It is stuck indefinitely on "Loading catalog data in progress." After inspecting the console, I found a major authentication flaw in your API connection: {"message":"1 validation error detected: Value null at 'shopifySessionToken' failed to satisfy constraint: Member must not be null"}.

How is it possible that the session token is null when the connection is through Shopify's own platform? Furthermore, the API response confirms that the operation bulk_fulfillment_update for my domain (ayaecofashion.myshopify.com) does not exist. This lack of maintenance is directly affecting my sales and inventory management. Please address this backend failure immediately.

At first, we struggled to get the app working and installed and uninstalled it a few times. But once we followed the basic setup instructions properly, it worked flawlessly.

Previously, we were manually entering order details to fulfil orders through Amazon MCF. Now, every time we get an order in the UK or the US, we just click a button in Shopify. It has completely changed our workflow and allowed us to focus on growing the business instead of managing fulfilment. We were even thinking about setting up our own warehouse, but now 90% of our shipments go through Amazon services via this app.

I was excited about this app as it promised to simplify my fulfilment process. I’ve used MCF before and expected this to remove the need for manually entering customer details. Instead, orders are sent to Amazon but remain stuck in “processing” and never get fulfilled, an issue others have also raised. Seller Support has been extremely poor — a 45-minute investigation resulted in generic responses and no resolution.