You can either automatically fulfill your FBA orders or manually fulfill them. Either way works perfectly with FBA Shipping by ByteStand. You just need to update your Shopify settings to tell your store what you want to do.
These settings are in your Shopify Admin under settings >> checkout >> order processing
When you get there you are presented with the options outlined below.
This is a Shopify functionality. This is not controlled by the FBA Shipping app. This setting applies to all orders. There is not a way to only automatically fulfill FBA orders and not also mark all other orders as fulfilled as well.
If you fulfill some orders through Amazon and some orders manually we suggest that you choose the setting that fits majority of your orders. If most of your orders are manual that you must ship out, we suggest turning off automatic fulfillment. At that time you would have to click ‘Request Fulfillment’ on each FBA order. But, you could accurately mark your manual orders as complete when appropriate. If most of your orders are FBA orders we suggest you keep automatic fulfillment turned on so you only have to check on your few manual orders!
At this time we are not aware of a way to ‘Hold Fulfillment’ of orders.