Assuming you have legally obtained a copy (by ripping your own UMD), here is how to set it up.
Use a stable internet connection. The file is large, so interruptions can corrupt the ZIP. download the sims 3 ppsspp zip file work link
Because The Sims 3 does not exist as a native PSP game, you cannot find a legitimate PSP "ISO" of it. The file you are looking for is typically a fan-made conversion where a modder wrapped the mobile version of the game into a PSP format (often using a tool like PSPKVM). Assuming you have legally obtained a copy (by
Here is how to properly set up PPSSPP to play this specific version. download the sims 3 ppsspp zip file work link
If you want to play The Sims on your mobile device via PPSSPP, stick to the games that actually exist: