Headless mode allows you to run a virtual machine in the background.
UTM needs to be open while the headless virtual machine is running.
To setup headless mode, open the virtual machine configuration and delete any display device as well as any serial device that is set to “Built-in Terminal” mode. It is highly recommended that you set up at least one serial device in one of the other modes so that you can communicate with the virtual machine. See this page for more details.
You can control headless VMs through the UTM interface or with the scripting interface.
macOS 13+ You can also disable the dock icon.