Create and override for defaultsetpagetitle.php

Copy the file components/com_jevents/views/default/helpers/defaultsetpagetitle.php to templates/YOURTEMPLATE/html/com_jevents/helpers/ and edit its content e.g. this would put the category name ahead of the event title

<?php



/*

 * To change this template, choose Tools | Templates

 * and open the template in the editor.

 */



use Joomla\CMS\Factory;



function DefaultSetPageTitle($view, $ev_title)

{



	// Get menu item id



	$newparams = Factory::getApplication('site')->getParams();

	// Because the application sets a default page title,

	// we need to get it from the menu item itself

	$menu = Factory::getApplication()->getMenu()->getActive();



	if (isset($menu->query["layout"]) && $menu->query["layout"] == "detail")

	{

		$newparams->def('page_heading', $newparams->get('page_title', $menu->title));

	}

	else

	{

		$event = $view->data['row'];



		Factory::getDocument()->SetTitle( $event->getCategoryName() . " : " . $ev_title);

	}

}

Sorry for the slow reply I had serious server issue I had to resolve as a matter of urgency

you can get the event id from

$id = $event->id();