They go into a very good explanation as to why Koch's postulates are necessary for proving it's existence and how the world renown virologists are fabricating their story.
The same rules apply to the rona.
Most microbiologists disagree. Koch's original postulates, based on my reading, have been amended (Koch himself amended one of them after he found counter-examples) with wide agreement from most modern microbiologists.
How do you know this is a "very good explanation"? That's the problem here. It could be completely wrong, and we don't have the knowledge and expertise in virology to see the faults in the reasoning.
So far I have not seen one actual reputable microbiologist assert that there is no virus. All I've seen is a couple of vocal anti-vax microbiologists dismissing the notion that there's no virus and that it hasn't been isolated. And when an actively anti-vax microbiologist says that kindof thing, I find it credible ... both because of their credentials and because they don't appear to be biased nor have they succuмbed to the pressure to approve of the "vaccine."