Thanks for getting back to this thread, @SmokinB. Let me clarify things about adding all items with the mark-up in the invoice. 

I recognize how relevant adding this feature is to your business. Currently, this option is unavailable in QuickBooks Desktop.

You will need to utilize the Add Time/Cost option on the invoice to add a mark-up, as mentioned by my colleagues above. For the complete process, please refer to the steps provided by SarahannC. 

Additionally, I've attached this article to help you manage your invoices in QuickBooks: Record sales transactions from customers. It also covers a link to see the complete list of workflows and other customer-related transactions. 

Keep posted if you have any other questions about adding items and mark-up in your invoices. I've always got your back. Wishing you continued success!