How to configure needed permissions

In the heyday custom app you've just created, under Configuration, click on Configure for the Admin API integration as shown below:

For the Product Search feature, set the following configuration:

-> Inventory: Read access (read_inventory)

-> Products: Read access (read_products)

-> Translations: Read access (read_translations)

For the Order/Shipment tracking feature, set the following configuration:

-> Orders: Read and Write access (read_orders and write_orders)

-> Third-party fulfillment orders: Read access (read_third_party_fulfillment_orders)

-> Customer: Read and Write access (write_customers and read_customers)

For shipment tracking with “View items” options, the same permissions as product search are required.