You might find an older version of Filza that is compatible with iOS 9.3.5 through various online repositories or the App Store's "Purchased" section if you've previously downloaded it. Keep in mind that using an older version may pose security risks, as you won't receive updates or patches.
Since iOS 9.3.5 is legacy firmware, the most common jailbreak tools are (for 32-bit devices like iPad 2/3, iPhone 4S) or Download Phœnix : Visit the Official Phoenix Site to download the : Use a tool like Sideloadly filza file manager ios 9.3.5 download
If you cannot get Filza running, try these: You might find an older version of Filza
If you need a visual guide on how to manage apps and system files on older iOS versions, this tutorial can help: Method 1: Installing via Cydia (Recommended)
To download Filza File Manager , you typically need a jailbroken device, as this version of iOS is considered "legacy" and does not support modern "no-jailbreak" tools like TrollStore. Method 1: Installing via Cydia (Recommended)