There are retroreflectors on the moon you can use to prove we were there.
If you deny X, and then you carefully deny anything that could prove X... what do you replace it with?
F.ex., I get how someone could disbelieve the current physics of motion. But then how do things move? It can't all just be dice rolls and unexplained magic.
If you toss out the way we understand things work... there still has to be a way things work!
If science doesn't work then what the fuck is this thing?