ProPresenter gives you a built in signal generator to use for testing your video signal. You have built in access to not only test patterns but ProPresenter will also display the outputs that are assigned to your screens.
To access this signal generator you will need to follow these steps:
Access ProPresenter Settings
Screens
Configure Screens
Test Patterns
You may need to select a pattern that you want displayed
Attached below is the test pattern setting screen on ProPresenter version 7.15
V1