How to calibrate video: AML-S905X-CC "Le Potato" 2GB / Raspbian

I am unable to see the toolbar: I have tested on 720 and 1080p TVs. I would like to recalibrate video so that the toolbar is displayed for my nephew, who is on another continent: the board will be shipped abroad.

For some reason, the origin (assume pixel at 0,0 is the upper left corner of display) is off the screen and the the command bar is not visible.

Where are the Raspbian controls to calibrate the display: move the origin to its proper location in the upper-left corner?

Turn off overscan on your TV or enable overscan on your board.

Thank you for the response. Please advise or provide a link as to:

  1. how to enable overscan on the board?
  2. how to decide whether to to turn off TV overscan or enable La-Potato overscan?
  1. Turn off overscan on your TV. Otherwise the image gets scaled and you get a lower resolution picture.
  2. Don’t do this but here https://www.google.com/search?q=x11+overscan&oq=x11+overscan