If you just gotta have a betting system because it helps quell the gambling anxiety or whatever, reverse martingale is fine. I made a video a long time ago about how it works[0] - but in essence, you only stand to lose your initial bet, and you have a bet schedule if you start winning. In "bet units" the way i do it is 1 unit until a win, then for each consecutive win: 2, 3, 3, 4, 5, 5, 5, 5 (etc). Everything after the first 3 unit bet is the casino's money you're gambling with, which is a good feeling. Note, this implies i consider each "round" that starts after a loss as separate from other rounds, obviously if you lose 20 times in a row and then win 3 games you're not suddenly in the green!
There's no system guaranteed to make you winner, but there are systems to help you lose more slowly, and reverse martingale is my go-to