AppearanceSetupForm.inc.php

<?php
namespace APP\components\forms\context;
use \PKP\components\forms\context\PKPAppearanceSetupForm;
use \PKP\components\forms\FieldUploadImage;
 
class AppearanceSetupForm extends PKPAppearanceSetupForm {
 
   public function __construct($action, $locales, $context, $baseUrl, $temporaryFileApiUrl, $uploadImageUrl) {
      parent::__construct($action, $locales, $context, $baseUrl, $temporaryFileApiUrl, $uploadImageUrl);
 
      $this->addField(new FieldUploadImage('journalThumbnail', [
            'label' => __('manager.setup.journalThumbnail'),
            'tooltip' => __('manager.setup.journalThumbnail.description'),
            'isMultilingual' => true,
            'value' => $context->getData('journalThumbnail'),
            'baseUrl' => $baseUrl,
            'options' => [
               'url' => $temporaryFileApiUrl,
            ],
         ]), [FIELD_POSITION_AFTER, 'pageHeaderLogoImage']);
   }
}