redmi note 8 pro to HDMI


if it a smart tv it should support cast, you don't need to connect a cable

Useless. That doesn't answer OP's question at all.

@kissandor I've been looking and found a thread on reddit about this. It seems that the redmi note 8 pro can not output image through its usb-c port, as it's using usb 2.0 instead of usb 3.1 and does not support nor the MHL neither the SlimPort standards.