set ticket purchase limit

functions.php

<?php


add_filter( 'tribe_tickets_get_ticket_max_purchase', 'rt_limit_max_purchase_et', 20, 2 );

function rt_limit_max_purchase_et( $limit, $ticket ) {
	$new_limit = 5;

	if ( $limit < $new_limit ) {
		return $limit;
	}

	return $new_limit;
}