Oh, I think I found the issue: it’s our security system that blocks queries from Unity from running on your website:
Since you don’t have a custom domain, there’s nothing you can do to bypass it, other than upgrading to Premium Hosting. But if you don’t have money and want a custom domain you can use on Cloudflare, you can get one from EU.org or PP.UA (that one if you have a credit card with some cents left on it and a valid phone number), even though I doubt it’ll work because cURL requests are blocked entirely even if you use it.