If you have to buy a new one, make absolutely sure it is the correct one for your scooter. There are many different kinds and the wrong one will mean a bad fit, incorrect depth and loss of kick travel or even worse, damage the spline on your kickstart shaft.
Fit the pedal rubber.
Push the kickstart pedal on to the engine shaft making sure the tab is as close to being in line with the stopper rubber inserted in the engine. Don't worry if the best spline to fit the pedal means the stopper is very slightly over or under, but more than a few mm is not good.
Affix the bolt from above like so...
And tighten using a split washer on the underside. You don't want this bolt getting loose whilst in use or the pedal WILL go missing.