Uncaught ReferenceError: variable is not defined

Hi everyone! New dev here and I am having trouble making php variables available on the front-end (i.e. localizing variables) using `wp_localize_script()`. Here is the code from my project that is related to the problem:

/*** functions.php ***/

require get_stylesheet_directory() . '/admin.php';
function enqueue_front_end() {
    wp_enqueue_script(
    'custom_fetch_script', 
    get_template_directory_uri() . '/assets/js/front_end.js', 
     array( 'wp-api', 'wp-api-fetch' ),
    '1.0.0', 
    true
);    
wp_localize_script('custom_fetch_script', 'custom_fetch', array(
        'root_url' => get_site_url(),
        'action_url' => admin_url('add-to-cart-logic.php'),
        'security' => wp_create_nonce('wc_store_api')
    )
    );
}

add_action('wp_enqueue_scripts', 'enqueue_front_end');

This is the setup recommended by AI, YouTube, Google and Stack Overflow. However, when I log the `custom_fetch` object to the console, this is what I see:

Uncaught ReferenceError: custom_fetch is not defined

I tried rearanging the functions in different ways to but that that didn't solve the problem either. According to the docs on wordpress.org, I also tried using the `wp_add_inline_script()` function like this:

require get_stylesheet_directory() . '/admin.php';
function enqueue_front_end() {
    wp_enqueue_script(
    'custom_fetch_script', 
    get_template_directory_uri() . '/assets/js/front_end.js', 
     array( 'wp-api', 'wp-api-fetch' ),
    '1.0.0', 
    true
);    
wp_add_inline_script(
  'custom_fetch_script',
'const custom_fetch = ' . json_encode(array(
      'ajaxurl' => admin_url('admin.php'),
      'nonce' => wp_create_nonce('wc_store_api'), 
      'root_url' => get_site_url(), 
   )),
  'before'
);
}

add_action('wp_enqueue_scripts', 'enqueue_front_end');

This to however did not solve the problem. Could anyone perhaps spot something I might be missing? If so, please let me know (If you need to see more code, don't hesitate to ask). Thanks in advance!