If you have multiple Amazon accounts synced with jungle Scout it can be hard to figure out which one you are working with. You also may want to rename your accounts which you can do at any time. These are only internal names for your reference inside of Jungle Scout and in no way change anything in your Seller Central account or Amazon account.
To add or edit your Amazon accounts names first navigate to your account settings and then to the 'Amazon Settings' section.
From here you will see all of the Amazon accounts and all corresponding marketplaces here:
Above you can see there are 7 Amazon accounts synced with this Jungle Scout account but only the first one is named, showing as 'Jungle Creations'. The other 6 need to be named.
You can do this by using the drop-down on the actions menu to the right of the account with the 3 dots '...' and then selecting 'Account Details' which will bring up this pop-up window:
Here you can name each account as well as select the default marketplace if you have more than one for an Amazon account. The default marketplace will be the one that is shown first when you select this Amazon account inside Jungle Scout.