(actually works both directions, e.g. if you have a portable display with only Type-C connectors like this https://www.hp.com/us-en/shop/pdp/hp-e14-g4-portable-monitor — BUT it can't power the display, you need to use another connection on the display for that.)
There is no HDMI over Type-C (there was an attempt at it, but it died. Probably for the better of not having even more Type-C confusion and interoperability issues.)