Step 1: Create a product with the Fuel app (if you have not already done so)
You can create the product so that it is not visible on your online store by checking the box to publish as "Hidden".
Step 2: Go to your Shopify Orders page and select "Create order"
Step 3: Search for and add the Fuel product you want to order
Step 4: Add or create the customer you want to ship this to
Step 5: Select "Mark as paid" and then "Create order" from the popup modal
Step 6: The order will then be sent to Fuel to be fulfilled and shipped
You can track all fulfillment updates within the Fuel app. Order details are sent to Shopify and to the customer as well.