When will free spins trigger for you?
Three to seven scatter symbols start the free spins, and no one can know in advance how often that happens. Each spin on the 7x7 grid is random, so one session may bring several triggers or none, whatever the RTP version. The return percentage describes long-run averages, not the single session a player sits down to.
Five RTP versions exist for this game, and the version in use is shown only in the game rules. Check that screen before the first spin, because the figure printed there is the one that applies to your play.
x50,000 the bet is the ceiling of this game, and it is reached very rarely. Hitting that cap is not a plan, and no session can be expected to approach it. Treat it as a limit on the win, not as a result to expect.