How do I keep the fog lights on in the night time in my 2016 Lacrosse

DRL or daytime running lamps are on during the day. If your car is equipped with fog lights, there should be a switch on the dash to activate them. What does your owners manual say?

When High beams are active fog lights deactivate, return to low beam and fog lights will resume (If you didn't turn them off on the dash)