Points to Note before flashing
All userdata like apps, media files, contacts, sms etc will be wiped after flashing the device.
These iPhones are clones (fake) there can be many variants of a particular device so do not flash preloader file unless its really necessary.
It’s a good practice to make a stock back up of the current ROM that’s on the phone before you flash them with any new ROM so that if anything goes wrong, you can restore back the one you made.
Flash at your own risk!