In my project the feedback slides have video, but it does not allow me to add close captions to them, it only allows me to add it in the normal slides.
You can add HTML5 Closed Caption for the video in Feedback Master (select the video > Properties pane > Media tab > Video > HTML5 Closed Caption)
Then, select a *.vtt file from the current project , or import one from your computer . Right after that, the Choose Language dialog will appear and allow you to select a suitable language. You can add multiple closed caption files in different languages to a video.
Thank you for your help.