Please follow the below steps -
Step 1: Log in to your Amazon Marketplace Portal
Step 2: Click on the Menu option. Refer to the image below for reference
Step 3: Navigate to Orders → Order Reports
Step 4: Select FBM Orders
Step 5: Select the required date range for which you want to import the orders, and click on Request
Step 6: Once the report is generated, it will be available under the Download Reports section. Click on Refresh and download to download the report.