Details about the Intel Flash Descriptor and unlocking it can be found at [Guide] Unlock Intel Flash Descriptor Read/Write Access Permissions for SPI Servicing - Special Topics / Intel Management Engine - Win-Raid Forum (level1techs.com). However, you don’t need to bother with that when you use a programmer to flash. If you followed the instructions as the guide says, you’re good. Go ahead and flash it with the programmer.