CORS issue with svelte kit and vercel

[Tobi-mmt]

I want to connect my svelte kit app with umami but looks like this does not work because of a CORS issue!

As an example I created a svelte kit app with the svelte kit create app command.
See https://github.com/Tobi-mmt/umami-cors-issue

I only added the script in the layout file.
See Tobi-mmt/umami-cors-issue@21d1cbe

I deployed it on vercel:
See: https://umami-cors-issue.vercel.app/

If I open the URL in the chrome browser it throws an erro in the console

What do I need to do, to make this very basic example work?