How to boot INTEL NUC DN2820FYKH without a monitor?

I bought a DN2820FYKH for my home server without a monitor, unfortunately, I found it cannot boot without a HDMI monitor that's turns on,

I read How to start DN2820FYKH without display

I deeply cannot understand why a NUC needs to boot with a HDMI monitor?!

I do hope you can release a new version of BIOS which can boot  without a HDMI monitor soon, is it possible and for how long?

Thank you!