Leveling the Machine

My machine is 1mm off level and I want to program the Z axis in the menu but when I enter the leveling option there is no end to the x and y axis. I’m Using the SKR pro board and would like to set them machine parameters for the distance from home so I can level it. Has anyone been able to do this?

What do you mean by “off level”? If there is a difference in Z height from one side to the other, that needs a different correction from Z a(n incoorect) fixed height above the spoil board.