That sticker looks like something you'd get from the sanctioning body during a tech inspection, kind of like they do with roll cages in racecars here in the states. They generally do the inspection ahead of the event day and put a sticker on the cage to indicate you passed, because the inspection is complex enough that they can't do it the day of. The sticker is not something that comes with the cage, as proper installation matters as much as the cage design.
I would ask the group that organizes the track day you're planning to attend what kind of tech inspection is required for your bike and gear. You may find that your helmet is fine, but you're missing some other important detail they require, like safety wire on certain fasteners or something.