Creating a quote based on an invoice
Make sure the Invoices & Payments tab is selected and select the invoice you want to base the quote details on.
Press the dropdown arrow under the Convert button.
From the dropdown menu, choose To Quote.
The quote will be created and opened in a form allowing the quote details to be edited. The form should look something like the following.
Edit the quote as needed. Press the Close & Save button to save any changes you make.