Yes! When you export a Composition as an mp4 video file, the subtitle cards are automatically embedded into the file. This means that services that support embedded subtitles may allow the user to enable or disable the subtitle text.
Note: Descript's embedded subtitles are not burned into the video. Burned subtitles are permanently visible in your video and cannot be removed.
If you would like to add burned subtitles to your video, Descript supports exporting your transcript as VTT or SRT subtitle files which can be imported to most popular video editing programs.