I haven't used alight motion in a year so it's a bit rusty but I think you press on the plus button select the rectangle and with the rectangle you press on the upper right corner you see a settings button was it? Then you can find the text saying "fill composite area" press that and then still with the rectangle you press on effects and search "copy background" and after that a simpler way of flipping it select the rectangle and go to the settings button and you'll see a text saying "flip horizontally" press it and your done
@@7_virat bruh you can just remove alight motion watermark and add your OWN WATERMARK which looks better, the alight motion water mark only has "alight motion" written on it literally everyonecan steal it and people will think they made the edit themselves whereas custom water marks are better because it lets the viewers know the rightful owner of the video idek if you gonna read all this but whatever