The QR code of your Smart Ticket in Quentro doesn't function like a barcode on a printed ticket; instead, it updates multiple times per minute to prevent duplication or counterfeiting.
That's why you can't print your tickets or replace them with a screenshot. A PDF file won't work for the same reason.
To enter the event, you need to show your Smart Ticket from the Quentro app. Once it's in your user account, you can access it even without mobile data or internet access.