(1) Go to Home > INVOICE tab > click on an invoice.
(2) Then click on ADD ITEM button.
(3) Then enter the item details to be added. (Name, Description and Price).
(4) Then click on the + icon.
(5) The entered values will be populated to the Add Item page.
(6) Enter the Category value > Then click on the SAVE button
(7) This new item will be added to the item list.
(8) Then click on the Save button to add the item to the invoice.
(9) The newly added item is now included in the invoice.