It’s not an exact science for sure, but moving the sensitivity slider will reduce false alerts. It might at the same time reduce real alerts, like if you wanted to detect small animals in your back yard.
When I am on travel, I have a camera in my living room looking at the inside of my front door. I have the sensitivity slider on that set to minimum The reason I do that is to try to eliminate false alerts due to dust particles when the IR lights are on. Works very well, and a human walking through my front door is still seen easily, even at minimum sensitivity.
Other things you can do: Change your detection box. Some people think the detection box has to include the whole person for Person Detection to work, for instance. No, you could have the box set at their feet, and when the feet enter the detection box the whole frame is evaluated for the presence of a person. So maybe setting the detection box lower may eliminate cars on the street.
You can sometimes also change the angle or location where you mount the camera to eliminate false triggers. Come at whatever you are interested in monitoring from the opposite direction, maybe.
It’s all a dance with pixel motion detection, however. So you can also add a PIR motion sensor to trigger the camera. You still need to be careful how you mount those, because they too can see cars on the street if you aren’t careful. Lots of ways to mount those, though. Above the door under an overhang, turned one way or the other, maybe even facing down on a flat ceiling with the bottom facing the door.
Think about your situation, and get creative.