Hi,
There is a custom action called "countdown timer" on the
Ecosystem (and many more custom actions)
But a wait function can do fine for this.
there is not really a traffic light tutorial,
a way you can do it is :
in the 1st state set the red light on and have a wait, then in the 2nd state turn of red and turn on green and a wait, and in the 3th turn of green and turn on orange and also a wait and loop it bacn to the 1st state