JToolbarHelper::unpublish('mybutton', 'index.php?option=com_mymodule&task=unpublish');In this example, "mybutton" is the name of the toolbar button, and "index.php?option=com_mymodule&task=unpublish" is the URL that the button should direct to when clicked. JToolBarHelper is a part of the Joomla Platform, which is an open-source PHP library used for building web applications and content management systems.