...
{#addProperty($document "showTicketUris" "true")}{#if(!$document.order.ticketUris.isEmpty())}{#set($ticketUri$ticketuri = "#joinParts($document.order.ticketUris)")}...
#if($document.order.ticketUris.size() == 1)} or download your tickets directly{#end#end}
The text "or download your tickets directly" is the text that will be displayed in the confirmation email.
The link "your tickets" must take the value "https://$ticketuri/".
...