To create one FBA shipping plan you must have integration with your Amazon seller center and have imported product offers:
To create a FBA order go to Menu -> Orders -> Orders -> “+” -> Wholesale
*(If you want to create FBA directly from Purchase order see this documentation -> https://orderadmin.freshdesk.com/a/solutions/articles/35000208435)
You have to fill in these fields:
*(Source – your Amazon integration)
Then press Add products and choose products and quantity of products that have to be shipped
Then press Save. Your FBA is created.