These snippets work together to allow us to add custom WooCommerce account menu links to any URL. See https://hookturn.io/add-custom-woocommerce-account-menu-links/ for more detail.

override-woocommerce-menu-item-url.php

<?php

add_filter( 'woocommerce_get_endpoint_url', function ( $url, $endpoint, $value, $permalink ) {
    if ( $endpoint === 'my-courses' ) {
        $url = home_url( 'my-courses' );
    }
    return $url;
}, 10, 4 );

register-custom-woocommerce-account-menu-item.php

<?php

add_filter( 'woocommerce_account_menu_items', function ( $items, $endpoints ) {
    $items['my-courses'] = 'My Courses';
    return $items;
}, 10, 2 );