Some of the ways we’ve seen these attached include double-stick tape, heavy-duty velcro, and even silicone.
3M makes a velcro option that seems fairly popular. But, if you’re on the lookout you can probably find something cheaper.
Nearly all brands recommend you secure your mat using a drill, and it will be the most secure(usually). But, it’s not always a good feeling committing to it. So, it’s a personal choice.