Create category for each user

How do you create a category for each user that registers?

I tried to add this in my functions.php

function fun( $user_id ) {
    $user = get_userdata( $user_id );
    
    wp_insert_term( 'My New Category', $user->user_login, array(
        'description' => 'Description for category', // optional
        'parent' => 0, // optional
        'slug' => 'my-new-category' // optional
    ));
}

add_action('user_register', 'fun');

I’d like to add a WooCommerce ‘Product Category’ for each user that registers but couldn’t figure out if this. Thank you for your help.