How To Root Fly FS455 Nimbus 11
1.Download And install MTK Android USB Drivers.
2. Download TWRP_root_files_FS455.7z and extract it.
3. Copy the supersu.zip file into the phone and turn off the phone.
4. Start SPFlashTool, click scatter-loading and select the file MT6737M_Android_scatter.txt from the TWRP-3-1-0-0 folder.
5. Press Download and immediately connect the switched off phone to the PC, after which the TWRP recovery will be performed, at the end a window with a green bird will pop out.
6. Disconnect the phone from the PC. press and hold the volume UP + POWER buttons in the menu to select “recovery”, and then TWRP will boot.
7. When you first boot into the recovery, if it asks “Allow changes to the system partition or leave it read-only” – allow it by sliding your finger at the very bottom of the screen to the right.
10. Select the item Install -> select the UPDATE-SuperSU-v2.82.zip archive and install it by making the swipe to the right (swipe to install).
11. After installing the archive, go back to the main TWRP menu and select Reboot -> system. After the done actions, the smartphone will reboot into the Android system already with root rights.