Google Meet / Google Meet Power User 

Send a chat message in a meeting

You can chat to contacts in the meeting, if you wish to share information with them without interrupting the flow of the meeting e.g. add to notes. Chats won’t be saved, but can be selected and copied e.g. to a Google Doc if required. Note that chats will be available for everyone in the hangout to see, but anyone joining the meeting will only see chat messages added after they have joined.

To send a chat message in a meeting:

If the chat window isn't open and a new chat message is sent from another meeting participant, an indicator will show on the Chat icon. Click on the icon to view the message.