If you have a project that has several different deliverables that are billed at different rates, you need per item pricing. You can set this up wherever you set up your project and it's deliverables and fees.
Add per item pricing to your fee structure project block. Click "Set up fees" in the project block header and choose "Per item"
Click a default deliverable or add a new one. Click "Products and services" to add a pricing structure from your product/service library or create a new pricing structure. This will be saved here for future use.
You can also choose to charge hourly per this item.
In project management, click the project name to edit it and choose "Per item" as the project fee type. Add a deliverable and fill in the details. Click "Select product/service" to access your product/service library or add a new pricing structure. This pricing structure will be saved here for use later.
Set the default rate and describe the units or choose to bill this deliverable by the hour.
When you create an invoice, choose "Add new line item" to access your product/service library. Use a saved product or service or create a new one. These will be saved for future use.
You can add this item to a project by hovering over the line in the invoice and clicking "Add to project."
To manage your project/service library, open it from any of the above locations. Use the edit pencil to make changes or the trash can to delete it from your library.