The short answer is NO.
Many users downloaded files labeled "GTA 4 PSP" from forums like PSPISO, only to find they did not work. Here is why: Pspiso.club Gta 4
Since PSPISO.club is no longer actively maintained in the same way it was during the PSP's prime, downloading random files labeled "GTA 4" carries risks: The short answer is NO
PSPISO.club was a repository for ISO and CSO files. If you have a modded PSP (Custom Firmware or CFW), here is how the process generally worked for legitimate PSP games: Since PSPISO
ISO folder on the root of the PSP Memory Stick.Downloading copyrighted games without permission is illegal in many jurisdictions. Always use legally obtained copies and be cautious downloading files from untrusted sources to avoid malware.