How do I convert a quote into an invoice?

To convert a quote into an invoice:

Go to the Quotes module under Sales in the left sidebar.
Select the quote that you want to convert to an invoice.
On the quote’s details page, click Convert at the top and select Convert to Invoice from the dropdown.
On the New Invoice page, check the details, and make the required changes to the invoice.
Click Save as Draft, if you want to send it later, or click Save and Send if you want to send the invoice immediately.