Question about HP Envy x360 14-fc0742nz

Yes, you can use the laptop's HDMI output to control a 4K screen at 60 Hz. The laptop has an HDMI 2.1 output that supports 4K at 60 Hz, but only as an output signal, not as an input. This means that you can connect the laptop to a 4K monitor and receive 4K 60 Hz, but not vice versa, i.e. you can use the laptop as a screen for other devices.