On most VIZIO SmartCast TVs, if you've already enabled the TV's closed captioning(CC) setting, the PBS app will also begin displaying closed captions when you begin watching videos.
If you haven't enabled closed captions yet, we recommend launching the PBS app, and then pressing the button on your remote labeled CC. This should bring up the VIZIO SmartCast TV menu where you can enable closed captions before returning to the app.
If your remote doesn't have a CC button, press the Menu button on your VIZIO remote. Use the arrow keys to highlight Closed Captions and press the OK button on your remote. Use the left and right arrow keys to change the Closed Captions setting to On.