Known rules before the spin, random outcome after
Seven RTP versions, from 96.50 to 96.56, set the long-run return but not how often the bonus round starts. Free spins begin with 4, 5 or 6 scatter-family symbols anywhere on the 6x5 grid, and the frequency of that event cannot be known before play. The result of one session stays random whatever the version, so a short run can end well above or well below the RTP.
The 96.50 version and the 96.56 version mark the two ends of the RTP range on this page. Which version this lobby runs is shown only in the game rules. Open the rules before the first spin, since the range tells you the limits of the return, not the return of your own session.
x20,000 the bet is the ceiling of Death Dominion, and a session reaches it very rarely. The multiple stays the same at every bet size, so the money amount grows with the stake while the chance of reaching it does not. Treat the ceiling as the edge of the game's range, not as a goal for any single session.