Custom code to configure WPEngine Geo Target

Our website has a few translations made through WPML Chinese, Japanese and English. There are 2 english versions UK and Aus because we have recently built a shop for the UK version.

The website is hosted through WP engine and we have purchased their Geo Targeting add on.
Geotarget overview: https://wpengine.co.uk/support/enabling-geotarget/
Dev doc: https://wpengine.com/support/developers-guide-geotarget/

We have installed the plugin onto the website but it requires some php to be written in order for it to work. There are a few examples of how it should be written, Code example on plugin: https://wordpress.org/support/topic/redirect-based-on-location-example-solved/ Another example: https://github.com/jpgamboa/geoip-example/blob/master/geoip.php

But PHP really isn't our forte hence why we are posting here.

We require Japanese users to be redirected to: https://example.com/ja
Chinese users to: https://example.com/zh-hans/mic-qpcr
English users to: https://example.com/en-gb
and everyone else to default to: https://example.com/