If you need to add a manual order or to place an order on customer's behalf over the phone, you would need to go to the Orders tab and then click the +Add Order button:

Once this is done, a new page would be open and you would be able to see the separate Order Info, Items and Customer Info sections which would contain related product and customer information and please see the example screenshots below:

After you add the Order ID and select the Service details, you can scroll down to the Items section, where the corresponding guid needs to be added. You can get the product's guid value from the All Products page, copy and paste it into the GUID field of the order and before you click the +Add Item button, you would need to double check and make sure the correct quantity is selected. The system will add the product, specified quantity and insert related product information (if available) and after that, you can scroll down to the Customer Info section and proceed with filling in the customer's information and additional required details in the Shipping Info
and Billing Info tabs.

The last step after all of the details have been added to the manual order is to click the +Add button at the bottom of the page and the order would be saved and displayed when you reopen the Orders tab: