There are two common issues that may affect your ability to use your iPad's on-screen keyboard. Both of which are easily resolved.
iPad won't show the keyboard
This is because your Socket Mobile barcode scanner is in HID mode. In HID mode, the iPad recognizes the scanner as if it were a wireless keyboard, so it thinks the on-screen keyboard is unnecessary.
If you run into this, double-tap the smaller button on your scanner. This temporarily re-enables the on-screen keyboard. Double-tap again to resume scanning.
Keyboard shows up, but "floats" in the middle of the screen or is split down the middle
If the regular QWERTY keyboard or the Green Bits PIN keypad is positioned mid-screen and blocking you from tapping on other fields or buttons, or there's a separation/split down the middle of the keyboard, your keyboard has become un-docked and/or split
To re-dock or merge the keyboard, tap and hold the keyboard icon at the bottom right and select Dock and/or Merge:
Note: if this issue is affecting the PIN keypad you use to sign into the Green Bits app, exit Green Bits and open another app such as Safari or Notes to pull up the regular QWERTY keyboard and access this setting.