2d character moves on the x and y-axis while only rotating at x-axis with joystick

I am making a 2d top down game with only using x,y-axis. Currently, I have made up, down, right, left movement with the Easy touch plugins' joystick. However, I can not find a way to make the character rotate to the x and -x direction when I press right and left. In other words, the character is always facing the same direction. I want to make the character change the direction when the character moves horizontally while maintaining the direction when the character moves up and down. Any help would be thankful.