Redirect to any page after LearnDash course is completed

course_complete.php

add_action('learndash_course_completed', 'course_completed', 10, 1);
 
function course_completed( $data ) {
    $course_id = $data['course']->ID;
    $slug_url = get_post_field( 'post_name', $course_id );
 
    if ($course_id) {
// After creating a "congrats" parent page and a child page with the same slug from the course. 
// More info here https://www.radiocastvps.com/how-to-redirect-to-a-page-after-completing-a-learndash-course/
        wp_redirect(site_url("/congrats/$slug_url"));
        exit;
    }
}