Put the phone in (Volume Down + Power, then release Power but hold Volume Down). In UnlockTool, select Gaster to Pwn the DFU.
: Use an original or high-quality Apple MFi-certified USB-A to Lightning cable; USB-C to Lightning often fails during PWNDFU exploits. Put the phone in (Volume Down + Power,
: The local data/apple subdirectory lacks the correct mapping for your explicit device configuration. Put the phone in (Volume Down + Power,