將YITH 紅利點數 生日設為必填

//將YITH 紅利點數 生日設為必填
add_action( 'woocommerce_register_post', 'ywpar_birthday_field_required', 10, 3 );
function ywpar_birthday_field_required( $username, $email, $errors ) {
  if ( empty( $_POST['yith_birthday'] ) ) {
    $errors->add( 'yith_birthday_error', '生日欄位為必填' );
  }
}

add_filter('ywpar_required_birthday', '__return_true');