Yes, but how you’ll play your video will depend on whether you have a file for your video or you’ll be playing it from a hosting site like YouTube.
Play a Video File During a Webex Meeting
In this case, you’ll just select the File option when you share your screen, then upload your video file to Webex. This short video tutorial by Webex shows you how.
Play a YouTube or Other Hosted Video During a Webex Meeting
In this case, you’ll still share your screen and play the video from YouTube (or other website), but you’ll need to select a couple of options so your video quality is good and participants can hear your audio; this Webex article explains them to you.