Your site may not be ready for Site Kit
Looks like you may be using a caching plugin which could interfere with setup. Please deactivate any caching plugins before setting up Site Kit. You may reactivate them once setup has been completed.
I tried the followings:
Deactivate all other plugins
Change themes
Reinstall site kit
Checked https status.
That’s not a very descriptive error message. It “may not be ready”? Why not just say what the issue is? Or at least whether it’s ready or not?
My guess is (and this is just a guess - it’s the best I can do given the information), that Site Kit needs to communicate to the WordPress API on your site, and this security system is blocking it:
If so, then I’m afraid Site Kit can’t be used on our free hosting.