I am trying to make the video in my survey mandatory. I need to make sure that the subjects watch the video before they moved on. I found out that the video can start automatically when the subjects navigate to the page with the line ?rel=0&autoplay=1. And I found that one can add a link that hide the next botton until the video ends (https://www.limesurvey.org/en/community-services/forums/can-i-do-this-with-limesurvey/99152-timed-question,-minimum-before-progressing#115349). But I am afraid that my subjects will exit the window before it ends. Is tha less intrusive way to make sure that they watch the video?