Tell it what you want to spend and which numbers you like. It works out exactly which tickets to buy.
Pick one.
Roughly. You can change it after you see the result.
Tap at least 6.
If you buy several tickets at random, two of them might share most of the same numbers. That is wasted money. This spreads your numbers across the tickets on purpose, so each ticket covers ground the others do not.
The promise it makes is a real one, but it is conditional. It only pays off if some of your numbers actually come up. Choosing better numbers is a separate problem, and nothing here helps with it.