For example, if the additional number key line is enabled, the keyboard on the OnePlus smartphone will appear quite large by default.

Depending on personal preferences or needs, the keyboard size can be selected from the following seven options:

Android 10 | OxygenOS 10.0
Step 1:  Open the  Settings
Step 2:  Tap on  System
Step 3:  Tap on  Languages & input
Step 4:  Tap on  Virtual keyboard
Step 5:  Tap on  Gboard
Step 6:  Tap on  Preferences
Step 7:  Tap on  Keyboard height
Step 8:  Set the  keyboard height
  1. Open the Settings
  2. Tap on System
  3. Tap on Languages & input
  4. Tap on Virtual keyboard
  5. Tap on Gboard
  6. Tap on Preferences
  7. Tap on Keyboard height
  8. Set the keyboard height

OnePlus Instructions