Anybody can show me where is the hard reset button on the Phantom 4 is located please? I look for it a zillion time , i can not find it?

There is no hard reset button on any of the DJI aircraft. There is a link button but you only use that if the RC becomes unlinked with the aircraft. That button is right above and between the USB port and SD card slot.
If you want to do a factory reset, install the Assistant2 software on your computer and plug the aircraft into it via the USB port and you'll see the option for dong a factory reset.

In the GO app homepage there's an icon in the top right (graduation hat), that takes you to the Academy section where there's the full PDF manual, tutorial videos, tips & tricks, and even a flight simulator.

Will it work with phantom 4 plus monitor

Will the Rc phantom 4 Pro could be link to a phantom 4 drone? I've tried with no success so far. Thank you