If you need to adjust the zoom on your POS, start by holding down two fingers on the screen like this:
When you let go, a menu will pop up that looks like this:
Tap on the "Exit full screen" option at the top:
This will reveal the browser address bar and tools menu in the upper right.
When you tap on the tools menu (the 3 dots in the photo above), you'll see a menu with zoom options:
Just tap on the plus or minus to adjust the zoom, and then tap on the dashed square at the far right of the zoom section to return to full screen.