The Closed Captioning Editor allos you to enable, upload, and edit closed captioning on a video.
While editing a course, click the Media icon in the authoring toolbar.
Open Bridge Advanced Video
Click the Bridge Advanced Video icon. From this interface, select the Video Card that you will be editing.
Open the Video Editor
To access the Video Editor, first, click the Menu  on the container that houses the video. Next, select Video Editor  option.
Open Closed Caption Editor
To open the Closed Captions Editor, click on the Closed Caption icon.