This is the transformer I use; cost $19 shipped thru amazon prime.
I got it for the screw terminals, and I like that it can be secured to the outlet w/a screw… plus it has a ground, built in PTC and a nice LED, its an all around winner and I am impressed w/its quality.
I am probably not the best case but of the 4 laptops I have around me, all different kinds only 1 has a 2prong.. My MacBook and ToughBook and my wife’s old HP Laptop all have a ground, her new work thinkpad however does not.. I believe a vintage 90’s laptop I just tossed out did not have a ground either but that thing didnt have any radios in it at all.