call of javascript function to external url always blocked by cors

I created a javascript function that have to be called every time someone clicks a button. This is the code present on file /wp-includes/js/utm.js:

This file is imported on footer.php:

When the button is clicked and the function triggered, I got this error on console:

Access to XMLHttpRequest at ‘https://xyz.com.br/’
from origin ‘https://wordpress-host.com.br’ has been blocked by CORS
policy: Response to preflight request doesn’t pass access control
check: No ‘Access-Control-Allow-Origin’ header is present on the
requested resource

I already added this code on functions.php:

And using both https://corsproxy.github.io/ and https://cors-anywhere.herokuapp.com/ on call with the xyz url, I got:

net::ERR_CONNECTION_CLOSED

Last, I used this plugin, but neither worked.

I don’t know what else I can do to transpass this error.