Most TicketsToDo experiences do not require you to print your voucher/ticket. You can check whether this is applicable for your preferred experience on the product page by looking for the ticket icon that specifies mobile or print tickets:
Most TicketsToDo experiences do not require you to print your voucher/ticket. You can check whether this is applicable for your preferred experience on the product page by looking for the ticket icon that specifies mobile or print tickets: