Let’s be realistic—iOS 9.3.5 is old. Filza’s last compatible version (3.7.0-ish) has bugs:

Filza File Manager is a popular file management app designed specifically for iOS devices. With its user-friendly interface and robust feature set, Filza has become the go-to file manager for millions of iOS users worldwide. Whether you're a student, professional, or simply a casual iOS user, Filza File Manager iOS 9.3.5 has everything you need to take control of your files.

Note: If you are on an iPhone 5 or newer 32-bit device, the process is similar. Ensure you are on the exact firmware version 9.3.5.

Once installed, you can:

[Update] Filza File Manager - iOS 9 compatibility, full changelog inside

Because iOS 9.3.5 is no longer supported by Apple, Filza must be installed through a jailbreak. Use the Phoenix jailbreak tool. Download the Phoenix IPA from PhoenixPWN . Sideload it using tools like Sideloadly or Cydia Impactor.