#wordpress polylang disable language in frontend

functions.php

<?php
if( !is_admin() && $pagenow != 'wp-login.php' && pll_current_language() == 'en' )
{
    wp_redirect(site_url().'/de/');
    die();
}

Hey, where can I apply these changes?

In functions.php of your active theme.

Hey, where can I apply these changes?

In functions.php of your active theme.

For some reason is not working on my website any chance it could be because I am using child theme?

Try to debug what exactly is not working. Does the first/second if clause work?

I am a bit newbie but to put that peace of code in functions.php you need to put it into a specific function, don't you?

@PatH007 not really 😁 PHP is a quirky language. Whatever is not in a function, is the 'main' code, even if it's spread across different files. I know it's weird, but that's how PHP works.

You could encapsulate it all in a function (more specifically, a procedure), if you really wanted to; but you would still have to call it afterwards, e.g.

function myProcedure() {
    // put all you wish to do in here
    return;
}

myProcedure();

which, indeed, seems a bit overkill (function calls use up extra memory & resources, too!)