I don't think you can. There's an option to have them hazard flash for emergency braking, but as far as I could tell no way to leave the bike with hazards/4-ways/park-anywhere-lights flashing. I have added a switch for them to a Honda motorcycle that was missing them, and in doing so learned that it's technically illegal to operate a vehicle with them on in nearly any state unless you are pulling over or have been in an accident.