function my_custom_ticket_header($collumns){
	$collumns = array( 'type' => __('Ticket Type','dbem'), 'price' => __('Price','dbem'), 'spaces' => __('Spaces','dbem'), 'available_spaces' => __('Available Spaces','dbem') );
	return $collumns;
}
add_filter('em_booking_form_tickets_cols','my_custom_ticket_header',1,1);<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="https://odermatt-lm.fe-labs.ch/wp-sitemap.xsl" ?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"><url><loc>https://odermatt-lm.fe-labs.ch/events/racletteplausch-2021/</loc></url><url><loc>https://odermatt-lm.fe-labs.ch/events/kommunal/</loc></url><url><loc>https://odermatt-lm.fe-labs.ch/events/badenfahrt/</loc></url></urlset>