You can use the Redirect Tool to bring external web sites right into your course. In this case - video chat using appear.in or Zoom (links in left nav).

If you want a video chat dedicated to your course, like the ones in navigation on the left, then follow these steps. BONUS: appear.in has a Chrome extension that will notify you anytime someone enters your room.

FIRST

go to appear.in and launch a room. Make up a name for the room with which you can live.
Click on Claim Room (upper right). You will be prompted to create an appear.in profile.
The room is now yours. Customize the room if you like, you can always go back.
Click on the Copy Link button (top).

THEN

Now go to your course.

Click on Settings (bottom left)
You should be on the Apps tab. Click in the Filter by name field and type in the word "Redirect".
This will find the app we need. Click on the Redirect Tool icon (arrow).
Click on the Add App button (beneath the arrow icon)
Enter "Video Chat" (or whatever you like) into the Name field. This is how appear.in will be in your course navigation.
Paste the link copied in previous steps into the URL field.
Uncheck Force open in new tab (if you want it to stay inside the course)
Check Show in Course Navigation
Click Add App
Refresh the page and your new link should be in the course navigation.