I reached out to Wirecast support about using the Wirecast Virtual camera with Easywebinar. Below is what they sent me back which I figured I’d pass along in case you get other questions:

"Thank you for contacting Wirecast support.

1. Make sure Easywebinar is not running.
2. Launch Wirecast and create a new empty document.
3. Go to the Output menu in Wirecast and select "Virtual Camera Out".
4. In the Virtual Camera Out menu, select the resolution you wish to use, if you want to use the Wirecast Virtual Microphone (to send audio from Wirecast) and last, select START.

Now launch Easywebinar and go to where you would select the camera and the sound input device (i.e. microphone). If Easywebinar can support the Wirecast Virtual Camera then it should show up on the list of cameras and the Wirecast Virtual Microphone will appear on the list of audio devices.

This knowledge base article gives an example of how to Wirecast Virtual Camera with online meeting software Zoom.