Enter into your Chrome Browser (make sure you are up to version 77)
1. Open a Chrome browser and search chrome://flags/ in the address bar.
2. Search Global Media Controls.
3. On the dropdown box make sure to select Enabled.
4. Click Relaunch Now (bottom right).
5. You'll now see a Play button in your toolbar when you start one of the tabs with audio (YouTube/Pandora, etc).
Embedded below is a GIF followed by a 56 second YouTube tutorial.