There are probably a couple of ways to get this to work, but honestly the easiest way is to use switches that are natively compatible with HE (which are usually not wifi) and use a basic rule or the room lighting app to do it.
If you want to try something to make use of your current Sonoff switch (not really what I recommend) you could:
(1) See if someone has written an interface for this Sonoff switch. If there is an open API someone might have done it. If there is and you can control the Sonoff switch directly from Hubitat something like the basic automation app would work. Your best bet is to search the forums here. I did find a couple of references to switches but not sure if there's actually a working integration.
(2) You could expose your HE motion sensor to Alexa and create a routine using Alexa. I'm not sure Alexa's routines have enough flexibility to do this easily, though. You might have to create a rule on HE that only enabled the motion sensor between sunset and sunrise, and then a corresponding routine on Alexa that used the motion sensor to turn the switch on and off. While this would likely work it would definitely be a chewing gum and duct tape solution and there might be a delay turning on the light. It would also be a pain to troubleshoot.
What kind of trisensor is it?