Easily refuted since Jesus was written about by two prominent historians of the day. Josephus and Tacitus. But I suppose facts don’t mean diddly to athiests...
Jesus was written about in the four gospels plus Paul’s letters plus Hebrews, James, Jude, etc., all of which were circulated at a time when they could have been refuted by people who were actually there. They were also circulated widely and to a general audience. We literally have nothing like this for any other figure from the ancient world.
I like the references to Josephus and Tacitus because Josephus is clearly anti-Christian, but Christians can’t let the atheists exclude scriptures as historical documents in the debate. It’s like us fighting with all our best players sitting on the bench while we bring in the third-string walk-ons and a few guys who were sitting in the crowd.