Once the quote you've sent off has been approved, you will need to replicate this inside of Bizzly. You can do this using the controls under the 'Convert to Invoice' header.
This will put your quote in to an accepted state in which you can now click the 'Convert to invoice...' button under the same 'Convert to Invoice' header.
This will now open the invoice creation screen with all of the quote details pre-filled. Follow this article to learn how to create an invoice and to continue the workflow.
This will put your quote in to an accepted state in which you can now click the 'Convert to invoice...' button under the same 'Convert to Invoice' header.