PLEASE ANSWER sincerly My friend says that Holocaust is not real because the Nazis only gassed victims of some disease with Zyklon B to fix them or stop it from spreading or something. And then he sai

PLEASE ANSWER sincerly

My friend says that Holocaust is not real because the Nazis only gassed victims of some disease with Zyklon B to fix them or stop it from spreading or something. And then he said that chimneys on gas chambers and lotss of other stuff were added later to make the "Nazis look bad" Lol he actually said that.... Can some please explain this me thx, cuz im clueless