Do not click on the "Manually Processed" button unless you have created the proper QuickBooks Online documents for the corresponding Amazon transactions.
When an import fails, you'll be notified. Take a look at the notification to see how to go about fixing it.
This button skips the import for that particular transaction, so clicking on the button without creating the right documents will mean that your order, inventory, or accounts will be inaccurate.
If you've manually created the proper documents for Amazon transactions, then you can click on "Manually Processed" so that the warning notification will go away. We'll mark that transaction as Manually Processed.