What directions are you using to install, setup, and use the application?
BTW, your image is atypical of what people see when the app does not work. People will usually see a mirror image of that, with the text reversed.
Make certain that the regular EOS Utility is not running. Make sure that the EOS Utility Launcher Service is not running, too.
You must have a subscription in order to use the “Pro” version of the Webcam Utility. The installation instructions tell you how to select the “free” version, which does not require a subscription. These instructions are available on the Product Support Page for your camera model.
Here is a screenshot of how to find the installation instructions. I strongly recommend that you click on both links and read through all of the instructions.
Here is a partial screenshot of the installation instructions.
09/26/2023: New firmware updates are available.
08/18/2023: Canon EOS R5 C training series is released.
07/31/2023: New firmware updates are available.
05/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
03/30/2023: New firmware updates are available.