Simple motions sensor -> turn on light

There’s a little more to it than that. There is an option under hello home actions to control a light from a motion sensor, but you have to also be changing the mode or the option doesn’t even appear. However, the good thing is that from a hello home action, you can control events for devices from different device classes all off the same motion sensor trigger. See:

And this topic lists some of the differences between using a shortcut group or using a hello home action: