First you need to open Customize Design, you have two ways:
ā From the Reelfy main menu, click Customize, then in Site Section click Customize
ā From the Reelfy main menu, click Widgets, then in Videos Section click Customize Design
At Customize Design, please select tab Site Section, at General, go to Play Video, here you can select not auto play video, auto play or play when mouse over video.
Finally, please save your change before leaving.