Progressive jackpot — it's a main prize for all slots and games. Win amount increases with each played spin. So the more players place bets, the faster jackpot grows.
Jackpot amount is shown in rubles. You just need to play slots and games to scoop a Jackpot. The more bets you place, the higher is the chance to win a Jackpot. If main prize is won, it will start accumulating again from some initial amount.