How to Flash Stock or Custom Rom using SP Flash Tool :-
Step 1: Download and extract the firmware on your computer
Step 2: Open the SP Flash Tool and load the Scatter File from the firmware folder.
Step 3: Install the USB Driver (skip if drivers are alredy installed).
Step 4: Turn Off your SmartPhone
Step 4: Click on Firmware Upgrade/Download Button in the SP Flash Tool.
Step 5: Connect your phone to the computer using the USB Data Cable.
Step 7: Wait for Finish or Pass.
Important Notes: Take a Backup of your SmartPhone data before Flashing or Update Firmware as because during the Flashing process your personal data will be removed permanently