Welcome to the QuickBooks Community forum, Justin. I see you're looking for guidance on creating a change order in QuickBooks and seeking advice on using BuilderTrend, a construction software that integrates with QuickBooks.

Regarding the "add change order window" in QuickBooks, it typically pops up whenever you make edits or add a line item to the estimate. You may have missed seeing this window if you clicked the "Add" button quickly.

As for using BuilderTrend, it's great to hear that you are exploring this software. If you are looking for further information or a learning experience about using BuilderTrend in conjunction with QuickBooks, I would suggest visiting their respective community page. They should be able to provide you with specific guidance and resources to help you make the most of the integration between the two platforms. 

I'm adding these resources on how to convert your estimate into an invoice:

• Get started with customer transaction workflows in QuickBooks Desktop
• Set up and send progress invoices in QuickBooks Desktop

With that information, it should clear some confusion. If you have more questions about changing the order in QuickBooks, do leave a post whenever you have other questions. Take care!