Please help me, I not a web developer but want to learn to fix these problems

function blogger_query_vars_filter( $vars ) {
  $vars[] = "blogger";
  return $vars;
}
 
add_filter('query_vars', 'blogger_query_vars_filter');
 
function blogger_template_redirect() {
  global $wp_query;
  $blogger = $wp_query->query_vars['blogger'];
  if ( isset ( $blogger ) ) {
    wp_redirect( get_wordpress_url ( $blogger ) , 301 );
    exit;
  }
}