On this page, you will find the official link to download Fly Fly IQ4504 Stock Firmware ROM (flash file) from GoogleDrive. Firmware comes in a zip package, which contains Flash File, Flash Tool, Driver and How-to Manual.
How to Flash
Step 1: Download the firmware on your computer or on your mobile.
Step 2: After downloading extract the firmware.
Step 3: You will get update.zip file.
Step 4: Copy the update.zip file the phone sd and flash it through the recovery mode.
[*] Take a Backup of your personal data before flashing or installing the firmware on your smartphone. As this helps you to recover the personal data whenever any thing wrong happens.