-Enter the account name: enter any name.
-Enter the country: enter your country.
-enter the seller ID: the seller ID of the seller.
-Enter the token: enter the token generated.
-Using FBA for fulfillment: if you choose yes, then your inventory of FBA will be sync. to your app and vice versa.
(Note: to get the seller ID and token refer to the Help PDF provided on the top of the same box and follow the mentioned steps)