Open FlashTool_v5.1220.00

Click on Scatter/Config File & select cfg File

Click
on option & tick on USB Download/Readback now Scroll down to Backup
and Restore & tick on Backup ->Download/Format -> Restore

Now finaly click on Download & plug USB cable to your powerd off phone

Wait for finished & Enjoy......(if failed try again)

Flashing Hints:No boot key needed for flash this phone just connect power phone.