The Send message connection method works in a similar way. It allows you to send a plain text message to a remote Host machine and the message is immediately displayed on the remote computer's screen. This way, you can also broadcast a message to multiple computers. For more information on the Send message connection method, please refer to this Documentation page.
Alternatively, while in the Full Control and View connection mode, hover your mouse over the top edge of the screen to reveal to toolbar and click on the Text chat icon. This will enable the mini-chat panel and also open the mini-chat window on the remote Host machine.