I made a simple web app using the App template in my ArcGIS online.

Now that I am finished I want to go back and modify a couple of things. Specifically I want to change the verbiage in the
details pane.

When I go back to the app in AGOL it give me a configure app button, but I only see check marks to turn tools off and on. How to I change the verbiage in the tool?
.