Go to Software update menu, disable Auto download over Wi-Fi
Connect phone to Internet via WIFI
Change phone's Date to 10 Days back ! For example, If phone's date is 25 August 2019, change it to 15 August 2019
Go to Software update menu, press Download and install to Update Phone's firmware via Wi-Fi
You may see "Registering" and then Register OK on screen, that means all is Done, wait for it to finish and then exit Software update menu.
Go to Developer Options, Now you can see "OEM Unlocking" there, Turn it ON.
Connect phone to Internet via WIFI
Change phone's Date to 10 Days back ! For example, If phone's date is 25 August 2019, change it to 15 August 2019
Go to Software update menu, press Download and install to Update Phone's firmware via Wi-Fi
You may see "Registering" and then Register OK on screen, that means all is Done, wait for it to finish and then exit Software update menu.
Go to Developer Options, Now you can see "OEM Unlocking" there, Turn it ON.
