Within Resources, you have the option to add a closed-caption file to your videos in WebVTT, or Web Video Text Track, format.
If WebVTT isn't an available format in your video-creation software, there are free conversion tools available online. Use a site such as 3Play Media to convert your caption files to the proper format. Simply choose the WEBVTT output format, paste in the caption file content, and click “Convert My File.”
Once you have a properly formatted file, upload it to Resources and attach it to the video in the video's Properties section. Then, make sure that the "Closed Captions" option is checked off in the settings where that video is displayed.