Ah, sorry, I just re-read the original thread.
It seems you are using a Raspberry pi. As far as I’m aware, these are equipped with arm-based processors, so they require special executables specifically made for them.
From what I can tell, the download page for the Itch app only offers a x86_64 version of the executable, so this can’t run on arm-based processors (so it can’t run on raspberry pi).
My familiarity with hardware isn’t that good, but the error “Exec format error” should mean the executable is not suitable for the current processor. For more information, you can try searching online for keywords like “arm architecture” and “x86_64 architecture”.
I’ve searched online, and the Itchio app is open-source, that means technically someone can compile it for arm processors and make it available to run on a raspberry pi. That’s however something difficult to do for a user still getting used to the terminal, not sure if it’s worth checking on some online community?