See New Features Rolling Out Soon
On the left I used 'Embed URL' from the INSERT menu. I entered the URL 'hangouts.google.com'.
I inserted the button below using this code in the Insert code section of the Embed edit function. Apparently embedding this no longer works, however.
<script src="https://apis.google.com/js/platform.js" async defer></script>
<g:hangout render="createhangout"></g:hangout>
Go to meet.google.com (or, open the app on iOS or Android, or start a meeting from Google Calendar).
Click Start new meeting
Choose the Google account you want to use.
Click Join meeting. You'll have the ability to add others to your meeting, too.
On the "Your meeting is ready" copy the meeting URL.
In the By URL section of the Embed function of your website paste the URL.