Manage WordPress Errors

Hello,

I am building a custom registration plugin and had everything working all right, except showing the eventual errors on the front page.

This is a brief example of the functions I’m using, some of the code has been cut out for “keeping it simple” reasons, but mostly similar with code from wp-login.php:

add_action('init', 'rms_check_login');

function rms_check_login() {

   $user_login = sanitize_user( $_POST['username'] );
   $user_email = apply_filters( 'user_registration_email', $_POST['email'] );
    ........................................................
   // check form fields for errors
   if ( $user_login == '' ) {
      $errors->add( 'empty_username', __( '<strong>ERROR</strong>: Please enter a username.' ) );
   }
    ...................................................................
   $errors = new WP_Error();

   if ( $errors->get_error_code() ) {
       // !!! need to capture errors and show them on the front-end !!!
       return $errors->get_error_message();
   } else {
      // insert new user and send notification
      $user_pass = wp_generate_password();
      $user_id = wp_create_user($user_login, $user_pass, $user_email);
      .................................................................
      wp_redirect( $redirect_to );
      exit;
   }
}

I don’t know what I’m doing wrong but I am not able to capture the eventual errors and show them on the front page, please help!

The custom registration form is part of a regular WordPress page (e.g. https://mydomain.com/registration-form/).

Thank you very much for your time and looking forward for your thoughts.

Best regards.