In Accounting 2.0, the Invoice Inbox page is where invoices are entered. 

To open this page, select Invoice Inbox on the left.

Then, on the top right, select the Invoice drop down and Add Invoice.

In the below screen, enter the invoice information.

It may be easier to attach a copy of the invoice backup to help with the entry process too. To complete this step, either drag & drop the file in the below section, or click on the box to browse the folders of your computer.

By clicking on the backup, you can view the invoice per page and use this as a guide for entry.