The Edit Quote action is only available in the new quotes version
You can edit a quote only when it is in open status.

This action allows you to modify one or more aspects of the quote based on your requirement, instead of having to create a new quote from the scratch. You can edit the plan or addon quantity, price, the subscription start date, notes, signature, and other elements in the quote.

There is also an Edit quote API call for this action.

Once you edit the quote and save your changes, a new version of the quote is created. You need to resend the email with the updated quote PDF and the quote acceptance link in a new email. The older link for quote acceptance becomes invalid once the new version of the quote is generated.