A: PPSSPP does not use PlayStation Trophies. It allows achievements only via RetroAchievements (optional feature). Custom saves will trigger RetroAchievements, but it's considered soft-cheating.
Because Ultimate Ninja Impact is so popular, many modders create custom versions of the game ISO. These are often called or "Road to Boruto" mods. Naruto Shippuden Ultimate Ninja Impact Save Data For Ppsspp
Even with the correct file, issues arise. Here are the top three fixes: A: PPSSPP does not use PlayStation Trophies