It sounds like you're asking about Farming Simulator 19 (FS 19) on PPSSPP, the PSP emulator for mobile/PC.
However, there's an important clarification: Farming Simulator 19 was never released for the PSP. The last Farming Simulator game officially available on PSP was Farming Simulator 16 (or Farming Simulator 14/16 in some regions).
If you’ve seen a “FS 19 for PPSSPP” download, it is likely one of these:
Here’s how to do it legally and safely: Download For Fs 19 On Ppsspp
Obtain the game legally – You can buy a UMD copy of Farming Simulator 16 (PSP) or buy it from the PlayStation Store (if still accessible on a real PSP or PS Vita).
Then dump the game into an ISO/CSO file for use with PPSSPP.
Recommended sites for game info (not direct download links – those often contain malware):
Avoid "FS 19 for PPSSPP" – Any site claiming to offer FS 19 on PPSSPP is fake, likely containing viruses or adware. It sounds like you're asking about Farming Simulator
Here is the secret that searchers of "Download For Fs 19 On Ppsspp" actually need: Play the mobile versions directly.
Giants Software released Farming Simulator 18 and Farming Simulator 20 (and recently 23) natively for Android and iOS. These games are visually superior to any PSP game and feature modern equipment.
Why use the Native APK instead of PPSSPP? A mislabeled ROM of Farming Simulator 16
If you are determined to use the PPSSPP emulator to simulate FS 19, here is how to customize Farming Simulator 16 to feel like FS 19.
You need a "ROM" or "ISO" file. Since downloading copyrighted games is a legal grey area, you must dump your own copy of the game if you own the physical UMD. However, for educational purposes, many users search for "Farming Simulator 16 PSP ISO download".
Warning: Avoid sites that pop up with "FS 19 PSP" banners. They are fake. Look specifically for "FS 16 USA/EUR ISO."