“The Raspberry Pi 4 not only has a new connector layout, but some of the connectors are of a different type than previous RPis. The power connector is now USB-C, to handle the extra current requirements, and the Pi can now support two HDMI monitors.
However, micro-HDMI connectors are used to make best use of the available space. This means you'll need and adapter or a new HDMI cable. This one seems ideal for the job.”
