Bonus timing and random results
Each spin lands a new set of symbols on the 5x3 grid, and the reels give no hint about what follows. How often the Free Spins round arrives is not known in advance. The result of one session is random, whatever the RTP of the version you play. No one can tell in advance which spin will bring the bonus.
Reels in Johnny Cash stop on symbols drawn under one RTP version, and that version is named only in the game rules. Open the rules before a session to see which version is in play. The return to player comes from that version, so the rules matter as much as the symbols on screen. The paytable and example bets on this page do not replace that section.
Reels that line up on a payline pay out, and the top of that scale is the maximum win. Johnny Cash caps that top at 2,077 times the total bet, and the ceiling is reached very rarely. Read it as the far edge of the pay scale, not as a number a session is likely to hit.