How do I notify you of units I want to ship to you for fulfillment?

First Log into your seller central account. Then go to the manage inventory section, then on the left-hand side, you can see a small tick box option visible just after the listings. you need to select all the product listings which you want to ship to FBA. then you need to create a shipment from your account and you need to pack all the order and ship in the box and then mark the shipment as shipped. Once the amazon FBA team received your products in fulfillment center they will add stock to your product and give you a prime badge.