1 - Click the menu icon (referred to as the “hamburger” icon)

2 - Scroll down to the Language section and click "Choose".

3 - Click “Select a language to add”

4 - Scroll down to English and select English (New Zealand). Click Add.

5 - Make sure English (New Zealand) is at the top of the list.
You can click “Move Up” if necessary.
Click OK.

Please Note: The setting below does not seem to override the language setting, so should not be relied upon.