WARNING: This overlay works only if you are connected to one server only.
If you were connected to multiple servers and the overlay crashed, try disconnecting from all servers and reconnecting to only one.

Setup

Download this project optionally as archive
Extract the archive and move the folder to where you want it to be
Open your TeamSpeak5 client and go to settings -> Remote Apps
Enable the "Remote Apps" feature
Open your OBS Studio
Add a new browser source to your scene
In the properties of your new browser source, select the Local File check box.
Click "Browse" next to the newly apperared "Local file" field
Now select the in step 1 downloaded overlay.html
Set the "Width" to 2000 and the "Height" to 1000 (This is just my own preference. If you have better values use them)
Now connect to a TeamSpeak server and check if it works. You may need to accept the remote app in your TeamSpeak notifications.

Troubleshooting

Restart the overlay

Option 1:
- Disconnect from all TeamSpeak servers and reconnect to just one.
Option 2:
- Restart TeamSpeak5.
Option3:
1. Open OBS Studio
2. Go open the properties of your browser source
3. On the bottom of the properties press the "Refresh cache of current page" button.