What is pressure refuelling and how does it work?
With a pressure fueling system, rather than fueling through holes in the tops of the wings, a fuel truck or fuel hydrant is used to push fuel into the airplane through a fitting at about 50 psi. The fuel fitting is generally in the right wing. A fueling control panel allows the fueler to fill the tanks to the amount called out by the flight plan.

These large aircraft still have an overwing fueling port for those times when the pressure fueling system is inoperative.

There is nothing to prevent fuel vapors from escaping to atmosphere.