There is no official release for the PPSSPP emulator because Forza Horizon 5 is an Xbox and PC exclusive title, whereas PPSSPP only emulates games originally released for the Sony PlayStation Portable (PSP).
To experience Forza Horizon 5 on mobile legitimately and safely, you can use modern streaming or specialized emulation methods. Legitimate Ways to Play FH5 on Mobile forza horizon 5 ppsspp iso download android mobile top