Here you can download all Official Oppo Flash File Firmware ROM for free. Oppo Flash File mainly use to fix the problems like stuck at boot logo, hang on the logo, remove screen lock, and many more other Android problems.
You can use this flash file to remove all types of screen locks like pattern, password, & FRP lock from your phone. Make sure, before downloading the firmware always check the firmware version & device model by click on the emergency call and dial *#899#, and then download the latest or same version of Oppo Stock ROM to flash your phone.
The firmware comes with a zip file and it contains Stock ROM, USB Driver, Flashing Tool & How-to Flash Manual guide.