Ivermectin works by interrupting nerve function of helminths(parasites). covid is a virus, not a multicellular organism with nerves.
I'm not saying ivermectin is useless, but why it would work for covid doesn't make sense (yet at least). Maybe it has some other mechanism to slow down covid that isn't fully understood.
This is the way many treatments work. For example, hydroxychloroquine was a treatment for malaria, but doctors found that some patients with autoimmune disease had their symptoms lessened or eliminated as they were treated for malaria.
So, it has become a milder treatment for autoimmune disease in some cases. The scientific community doesn't 100% understand why it's effective for autoimmune disease, but there you go. It seems to work in many cases.
I say this not as an expert, but as someone who has taken it and it has worked for me. I don't care that the mechanism is unexplained.
The mechanism by which Ivermectin works does make sense, and has been well-established. Look up any of the many binding studies on pubmed for example.
Regardless of this, the results of the great many RCT's speak for themselves.