You have to ensure that there are no gaps and spaces in the flooring and it is complete and perfect in every way.
How to do laminate flooring on stairs.
Step 1 preration removing carpet creaky stairs if your stairs have and overhang this need to be removed or the space below the overhang needs to be filled in.
Things i mention in this vid.
However installing laminate flooring on your stairs is a completely different matter.
Alternatively you could cover the overhang with plywood to make it level.
The first thing to do is to remove carpeting and check the stairs for squeaks and make sure the stairs are flat.
To install laminate flooring on stairs start by removing the overhang or the underside of the stairs with a jigsaw.
Laminate flooring installation on stairs.
Watch how to install laminate flooring on stairs video.
Here are the steps for installing laminate flooring on stairs.