I didn't-- actually not sure what SmartStart is. I just paired it normally- Devices -> Add Device -> Z-Wave (under add manually) -> Start Z-Wave Inclusion. Hubitat picked up right away when I held down the 1 button on the keypad for 3 seconds -- i entered the 5 digit code and it was all set.
I just searched the forums for SmartStart and found this video -- neat! i'll exclude the keypad and give it a try.