You can use any button you like on the dna theres thousands of choices my favorite so far are the light up leds but you have to make another circuit for it.
Heres breaks schematic for this type led switch.
Heres ecf's Vapant schematic for parallel switch led button switch using a transistor PN2222A on the atomizer output..
Outcome
The guy who asked how to do it, the switch, it was his 1st mod he hit it out the ballpark eh..