To collect an Online Estimate Approval, start by creating an estimate, then using the Email icon in the Estimate to send an email, making sure to select the box to Allow Online Approval.
Your customer receives an email with all the details of the estimate, as well as a button to Approve or Decline the estimate. Clicking that button will take them to the Online Agree + Deposit portal, where they can approve or decline each job in the estimate, and provide their credit card number to submit the deposit.