I suppose it is possible that some of the near death experiences are made up, or imagined, but no doubt many of them are real.
I have a friend who fell down a mountain. He didn't die, but thought he was going to. He told me about seeing "angels" on the way down. another friend encountered a climber who had been killed on Mount Shasta. He told of a woman and child in street clothes who told him to stay away, as the landslide was still coming down, and he could be killed himself. He wondered how they could have climbed such a mountain with no equipment. These people were soon nowhere to be found.
Of course, anectotal incidents are not scientific proof. How there could be scientific proof, I'm not sure.
Nevertheless, C. S. Lewis was right. I know that the soul exists, because I am one.