nRF52840 DFU(Secure_Bootloader example) Setting

I'm want setting Secure_Bootloader.(IAR compiler, SDK 15.3version)

I followed the following guide but got stuck in Step B.

I have installed GCC compiler toolchain for ARM, MINGW, GNU Make.

But sending a make command does not compile.

I set environment variables as follows.

Please tell me what the problem is.