When you first log in to Stratify, you will be prompted to add access to your Amazon seller account through what is known as their Selling Partner API (SP-API).
When prompted, all you will need to do is click OK and log in to your Amazon seller account.
Note: You must have a Professional Seller account to access Amazon's Selling Partner API, which is required for InventoryLab to access your Amazon account. In addition, InventoryLab only supports the US (.com) Amazon Marketplace at this time.
You will be redirected to Seller Central where you should log in with your Amazon seller account information.
You will be brought to a screen where you can review and agree to authorize InventoryLab's access to data from your Seller account. Make sure the checkmark is selected and click Confirm.
Amazon will complete the authorization and show you the message below:
You will then be returned to Stratify. You will receive a message stating your data is now syncing and will be imported soon. (Please note that the initial data sync process can take 12-24 hours.)
After your InventoryLab account has been connected to your Amazon Seller Central Account, check out this article and video on optimizing your settings in InventoryLab and Seller Central before getting started: