How to add additional Amazon credentials for different marketplaces in the app ?

How to add additional Amazon credentials for different marketplaces in the app ?

Open the App > Click on Configuration > Go to  Additional Amazon Marketplaces
Select the respective Market place from the drop down which should be different from that marketplace mentioned under Amazon settings and enter Seller ID & MWS Auth token for authentication.
Click on "Add New" button if customers want to add more Amazon credentials for different marketplace.  The other marketplace will only sync order and tracking.

For Multiple Amazon Marketplaces
Current functionality of the app is
If you are using our App for multiple Amazon marketplaces then the inventory will be synced with the same Marketplace that you have already set in the AMAZON setting under Configuration app

For Instance: If any UK order comes for Amazon FBA UK or any USA order for Amazon FBA USA and so on, then the order will be fulfilled by the App as per the registered marketplace and the tracking information will be updated respectively but the Inventory will be updated as per the Amazon Marketplace (Primary marketplace) under AMAZON SETTING in the Configuration page of the app

NOTE:
If you want the inventory should be synced with the specific marketplace then you need different Shopify accounts to configure the app individually .
> Also for additional marketplaces, You do not need to map SKU and they are auto-linked if the SKU matches exactly.