Congo Cash ceiling you will rarely reach
Decide how much you are willing to lose before the first spin, because nobody can tell you when the Free Games round will arrive. Its timing is not known in advance. The result of one session is random, whatever the return figure says over a very large number of spins. A short session can end far above or far below the amount you started with.
Open the game rules before your first bet, because only they state which RTP version is running for Congo Cash. Compare that version with the figure in the table on this page before you stake real money. A version that differs from the one you expected changes the return you can expect over time.
Read the maximum win as a ceiling, not an expectation, before you set your bet. Congo Cash can reach it only in rare cases, and no one can tell in advance whether a session will come close. Treat the top figure as the limit of the game, not a likely outcome.