Aww, that's a beauty of DJI ..

You can't have HDMI output straight from goggles when using DJI FPV system. Nor any other system other than using Smart Controller (which normally is used to fly Mavics) - plugging USB cable into it, running separate app and then getting HDMI out from Smart Controller
What
@rpossum was previously referring to is that theoretically speaking you don't need to be in goggles when flying using DJI FPV system - if you own Smart Controller you can have HDMI output from it and watch fpv stream from DJI FPV on regular monitor, yet .. what I was referring to is that this setup adds significant amount of latency which makes flying in fpv much riskier..