If you are a casual player wanting to skip a grinding section or test a build, stick to the and download the latest patches. If you are a power user who wants to invent new cheats or mod the game in real-time, Cheat Engine plus the RPCS3 Cheat Manager (third-party) is your best bet.
If your game crashes immediately after applying cheats, a cheat is likely conflicting with the emulator's current state. Turn them off one by one to find the culprit. Cheats Aren't Showing Up cheat manager rpcs3
: Most users use this to enable "Game Patches" (like 60FPS mods or resolution fixes). These are often curated by the community and can be updated directly within the manager. Cheat Manager for RPCS3: Design, Ethics, and Implementation