Itinerary, not paid tickets
Most tourist visa routes ask for a flight itinerary or reservation, not purchased tickets. This is deliberate — embassies know that buying non-refundable tickets before a visa decision is risky, and they do not want applicants to lose money if refused.
How to produce an acceptable itinerary
A flight reservation or hold itinerary from a travel agent, or a clearly labelled placeholder itinerary, is usually acceptable as long as it shows dates, route and your name matching the application. Avoid fake-looking documents — officers can spot them and they harm your credibility.
What to write in the application
If the application asks for ticket numbers, use the reservation reference where allowed, and keep the itinerary consistent with your hotel and date details. After the visa is granted, book the actual flights that match the itinerary you submitted.