Download the GTA_SA_Definitive_Edition.iso (usually from a reputable Mediafire link) and the accompanying SavedData folder.
To understand whether this download is real, you need to look at the technology behind the software. Gta San Andreas Definitive Edition Ppsspp Download Mediafire
The Definitive Edition was built using the Unreal Engine 4 for modern hardware (PS4, PS5, Xbox One, Xbox Series X/S, PC, and native iOS/Android mobile ports). The PSP hardware configuration cannot interpret or run this engine. What are you actually downloading? Download the GTA_SA_Definitive_Edition
emulator, you should look for the games that were actually made for the PSP: Grand Theft Auto: Liberty City Stories Grand Theft Auto: Vice City Stories Grand Theft Auto: Chinatown Wars A Note on Download Security Xbox Series X/S