Hi and welcome to the forum! Please don’t use AI to write your posts, as it tends to overcomplicate the context we need even more and not understand anything. Any future post written with AI will result in it being flagged and deleted.
Anyway, as for your problem, I think this is causing it:
Not even using a custom domain and Cloudflare will bypass this on the application you’re going to use to test it, as cURL (the library used by AppInventor as well) is blocked either way.