The PECOAir power cord ships under the top tray of the box, so lift the tray out first if you don’t see it. The socket is on the underside of the purifier: tip the unit gently on its side, plug the cord into the port in the base, and route it out through the cord channel. The channel also holds any extra length, so wrap the excess there before you set the purifier upright; it keeps the cord flat and off the floor.
Then stand the unit back up, give it 12 inches of clearance from walls and corners, and plug into the wall.