It sounds like you're looking for a way to download as a ZIP file for the PPSSPP emulator (Android/PC).
If you just want to test a PSP emulator, get GTA: Vice City Stories legally by dumping your own UMD or using a legit backup. gta san andreas ppsspp zip file download
Would you like safe steps to set up PPSSPP with a real PSP game instead? It sounds like you're looking for a way