This is also not limited to the newer devices like macOS Catalina’s Sidecar. As long as the main Mac is running macOS El Capitan or newer, the secondary mac can be running OS versions as old as Mountain Lion.
To use this, you will have to install the software in both Macs. Both of them will also have to be connected to the same Wi-Fi network, and there’s no wired option. That said, achieving this needs more than just software. The hardware component comes in the form of a dongle that you plug to the main Mac. This comes in USB-C or Mini DisplayPort versions. Luna Display is priced at US$69.99 (~RM293). That said, it doesn’t look like there’s an option to have them shipped to Malaysia. (Source: Luna Display via AppleInsider)
