How to set "DisplayPort Alternate Mode" in Windows 10?

[RayDFACM]

In my new Acer laptop, I want to use its USB type-C 3.1 port to connect a second HDMI monitor (I already use the standard HDMI connector in the laptop for the first monitor.)

I bought a Cable Matters "USB Type-C to HDMI Adapter" which SHOULD work but doesn't. (I already replaced the original one with a new one and it still doesn't work.) Upon reading a number of webpages, I suspect that this could be a software issue since there apparently is a "DisplayPort Alternate Mode" that needs to be somehow enabled through the USB 3.1 C port, but I have no idea how to do that. Windows 10 reportedly DOES have the "DisplayPort Alternate Mode" through the USB type-C 3.1 port.

I wonder if anyone here has any idea on how to proceed?

Thanks!

 

[RayDFACM]

Hmm... I think that the problem stems from the fact that the Acer laptop does NOT have hardware / firmware support for the DisplayPort. A Microsoft document reads as follows: "Windows 10 is capable of detecting DisplayPort/DockPort and MHI devices if the hardware supports those alternate modes."