Hey @Shawpnil. What class is being created for you to move around the level like that? Is it an empty Pawn class? or a Spectator class? or something else? You probably need to change some setting in whatever class is it that is being created when you press play.
For you to be able to change the speed in the packaged build then you would have to implement some kind of UI to let the player change the speed of that controlled class.
Hope this helps