Can I glue laminate down?

It is possible, but note that it is not recommended and it will make the warranty void.

The sub-floor must be perfectly level and damp-proof. Most probably it will be necessary to use a levelling compound and an appropriate damp proof layer. In addition, you will need a resin that provides sufficient adherence to the Laminate backing.

You will need to glue and screw (or nail) the laminate down to the stairs themselves. The glue should be a Liquid Nails® or "construction-type" glue dispensed from a glue gun. To ensure a stronger grip for the adhesive to the back of the laminate flooring plank I recommend "violating" the back of the plank by scratching the surface of the back with either a knife or screwdriver.