AI told you some garbage there.
Slot machines are here for entertainment and the thrill of a big win, which does happen, but they are not here to make money for the player.
The most common RTP in the online industry hovers around 96%, in the offline industry it can go as much down as 80%, but offline businesses that go that aggressive rarely deal with regulars, while we in online deal with regular players and want that they stay with us longer, so we have higher RTP's. That doesn't mean that you, specifically you, will get 96% back out of $100 gambled. No, this means that the game, on an average (a huge average) is giving out 96% back, but in most cases you don't see it because it comes back in increments. Someone might have a zero RTP, someone else a jackpot. It's a theoretical average. The point is to entertain you as long as possible for those $100, and the slot machine will be taking and giving as you continue to play. You might win, but let's assume you'll not.
And although the games have to be ISO/IEC 17025 compliant, if the casino is using a slots provider (e.g. Bgaming) then they can't change the RTP, it's baked into the game and managed by Bgaming, not the casino. So the Auditing part would go to Bgaming, which is a Malta Gaming Authority audited brand, so basically MGA is doing the Audit on them.
If the casino is using their own games, there's more room for scams, so check if they are "provably fair" (no, it's not a typo). However, I would never recommend to play on a non-licensed casino.