echo '<a href="index.php?option='.$option.'&view='.$view.'&id='.$id.'" target="'.$target.'">'.$link_title.'</a>';

<a class="lightbox" id="main_image_full_<?php print $image->image_id?>" href="<?php print $this->image_product_path?>/<?php print $image->image_full;?>" <?php if ($k!=0){?>style="display:none"<?php }?> title="<?php print htmlspecialchars($image->img_title)?>">

use Joomla\CMS\HTML\HTMLHelper;

$url         = 'index.php?option=' . $option . '&view=' . $view . '&id=' . $id;
$link_title  = HTMLHelper::image('images/headers/raindrops.jpg', 'Alt attrib for image');
$target      = '_blank';
$linkAttribs = [
  'target'       => $target,
  'class'        => 'btn btn-primary',
  'onclick'      => 'alert(123);',
  'data-link-id' => '4a5d7f6a455sf8',
];

echo HTMLHelper::link($url, $link_title, $linkAttribs);

use Joomla\CMS\Factory;

$app = Factory::getApplication();
// Получаем объект плагина
$revars = $app->bootPlugin('revars','system');
// Обращаемся к любому публичному методу плагина
// Получаем переменные
$variables = $revars->getVariables();
// Посмотрим что мы получили
foreach($variables as $variable)
{
   echo $variable->variable.' = '.$variable->value.' <br>';
}

$defaultUrlParams = [
            'format'        => 'CMD',
            'option'        => 'CMD',
            'controller'    => 'CMD',
            'view'          => 'CMD',
            'layout'        => 'STRING',
            'task'          => 'CMD',
            'template'      => 'CMD',
            'templateStyle' => 'INT',
            'tmpl'          => 'CMD',
            'tpl'           => 'CMD',
            'id'            => 'STRING',
            'Itemid'        => 'INT',
        ];

public function display($tpl = null)
{

     $app = Factory::getApplication();
     $this->pagination = $this->get('Pagination');

     // Flag indicates to not add limitstart=0 to URL
     $this->pagination->hideEmptyLimitstart = true;

     // Add additional parameters to pagination url
     $queryParameterList = [
               'catid'      => 'int',
               'project_id' => 'int',
               'language'   => 'string',
     ];

     foreach ($queryParameterList as $parameter => $filter)
     {
          $value = $app->getInput()->get($parameter, null, $filter);

          if (is_null($value))
               {
                    continue;
               }

          $this->pagination->setAdditionalUrlParam($parameter, $value);
   }

}