Step 1 - Click on [cc] on the top of the LiveWebinar Console.

Step 2 - The first part of it is MESSAGES, over here you can see your messages and also click through them to appear on everyone's screens as a closed caption.

or

You can also choose to type the captions live and press ENTER or ADD MESSAGE button.

Here is how it looks.

Step 3 - In GENERAL CONFIGURATION, you can choose if you want it to appear, download the captions, save them or load captions previously made!

Step 4 - In the last tab, DISPLAY SETTINGS, you can make adjustments to how you want it look like for example the colors of the boxes, texts, size and opacity and have a preview before making it go live.