LearnDash Redirect on Course Completion

LearnDash Redirect on Course Completion

// Adding Custom Redirection field in LD Courses
add_filter( 'learndash_post_args', 'add_topic_option' );
function add_topic_option( $post_args ) {
	
	// New Course field to add redirection link.
	$redirect_on_completion = array(
		'redirect_on_completion' => array(
		'name' => __( 'Redirect on Completion', 'learndash' ), 
		'type' => 'text', 
		'initial_options' => '',
		'help_text' => __( 'Add redirection on completion', 'learndash' ), 
		'default' => '',
		'show_in_rest' => true,
	));
	
	// Pass the new field in the topic fields array.
	$post_args['sfwd-courses']['fields'] = array_merge( $redirect_on_completion, $post_args['sfwd-courses']['fields'] );
	
	return $post_args;
}

// Redirecting to custom link on course completion
add_action( 'learndash_course_completed', 'redirect_to_link' );
function redirect_to_link( $data ) {
   
  if( empty( $data ) )  
    return false;

	$course_id = $data['course']->ID;
	$redirect_on_completion = learndash_get_setting( $course_id, 'redirect_on_completion', true );

  if( $redirect_on_completion != '' ) {
    wp_redirect( $redirect_on_completion );
	  exit;
  }
	
}

Redirect to where? How can I controle where it should redirect?

This is exactly what I'm looking for, but I wanted to know where to put the code? I added it to my child theme's functions file, but it doesn't seem to have added the redirection url field. Does it need to go into one of the plugin files? That would make it a pain during plugin updates, but well worth the extra step.

Also, where do I look for the new field? Is it going to be under the individual Course's settings…?