So many people view that as some impenetrable wall; but, it just isn't. First, the Van Allen belts fit the planet as a torrid, a doughnut if you please. Second, the intensity of those things were mapped by Earth satellites long before Apollo flew. Third, harm from radiation results from the combined affect of intensity, time exposure, and shielding.
Knowing all of this in advance, they designed a spacecraft of 3/8" thick aircraft aluminum with a 1/8" ceramic overlay. (Shielding) Apollo was launched at 75 degrees relative to the equator so as to exit the Earth vicinity via the doughnut hole, then turn toward the moon to pass only through the weak outer fringes of the belts. (Intensity) They passed through that fringe in about 20 minutes, I seem to recall. (Time Exposure).
Being forewarned did allow for appropriate preparations and planning. It seems most people think the Van Allen Belts were some kind of surprise.
Faking a lunar landing AND GETTING AWAY WITH IT would be harder than actually going to the moon. It would be a conspiracy that would involve hundreds of thousands of government and private contractors. None of whom have talked in 50 years.