Hi there, usertxbuildingco.
I understand that you want an option for your customer to approve the estimate or by simply e-signing. In QuickBooks Online, the only way you can let your customer sign an estimate is through the QuickBooks Online mobile app.
You'll want to continue using the Jobber by integrating it into QuickBooks Online. You can also find similar applications on the Apps tab.
Our product team is constantly adding new features to help you and your business. Visit our Blog so you'll be updated with our innovations and enhancements.
Post again here if you have more questions. Wishing you all the best!