(Solved) OH3 - Rule trigger but only if after sunset

No need for a script. Have a look over the Time of Day design pattern.

Basically, you need an unbound string item that you use to store the time of day (e.g. Day, Night), and then rules to change the state according to either time or astro updates. Then you can just use that item as your if condition.

You can get pretty complex with it. Personally, I just use a Day and Night, with the state changing at sunrise and sunset.