The details of a bunker order can be edited and maintained in the Bunker Management application.
When you have located the bunker order click it and the details will show in a panel (so called "drawer") on the right hand side. Details can be maintained directly in the fields.
If you want to add a product for a given order click the "+" button above the list of products. Then a dialog will show and allow you to enter the details.
If you want to edit the details of the bunker order line (bunker type, quantity or unit price) click the bunker order line and a dialog will show allowing you to change.
Bunker Type: If estimating bunker intake, the bunker type set will default to the grade this vessel is set up with in your vessel administration screen. If you need to change this you can do that in the below screen or when you actually place/create the order.