Management of your orders is done in Shopify. Shopify provides excellent documentation and support. Please familiarize yourself with the Orders section of the Shopify Manual.
IMPORTANT: If you are using the order automation of the NutriLoader, your orders are automatically being sent to Europa for fulfillment (you will get a notification as well), but showing the order fulfilled in Shopify is not automatic. Once Europa fulfills the order, they will send you an email with the order's shipment tracking information. You will then need to go into the order in your Shopify Admin and click to fulfill it there, entering in the tracking information provided by Europa. This will generate an email to your customer telling them that the shipment has gone out and the tracking information.