I do not see any plugs after my aeration.

Depending upon your soil type the soil plugs can be hard to find. Sandy soils allow the plugs to break down very quickly, almost as soon as we pull them out of the soil.  If you have a thick, lush lawn that is mown high, plugs can be hidden in the grass.  Check areas where there is less grass to see if you can see the plugs or holes in the lawn there.