Relative path to CSS and JS files hosted with GoDaddy do not work

I'm setting up a site in the GoDaddy provider and I'm having a problem causing the CSS and JS settings to be applied to the site because it appears all unchecked.

I ran a test to verify that the address passed in link href is correct and successful.

I made a test using a if inside the file index.php , this file is failing.

$filename = '../assets/_css/0_css_dashboard.css';
if (file_exists($filename)) {
    echo "O arquivo $filename existe";
} else {
    echo "O arquivo $filename não existe";
}

and the response from if was that the file exists ...
Any idea what might be happening or if I need to apply the link in any other way?