Australia Post - How to get the API access key?

In order to establish the Australia Post API connection you will need to enter an API key for the Postage Assessment Calculator at the very top of the plugin configuration screen:

Australia Post - General Settings - API Settings

Once your API key was entered and Save changes button hit, the API Connection Status should change to OK and turn green.

API access to PAC and Postcode Search

Obtaining an API key will require completing a form at https://developers.auspost.com.au/apis/pacpcs-registration.

Start by filling out your details in the form. After completing the data, click Submit button.

Australia Post - API access to PAC and Postcode Search

You should receive an email from Australia Post Developer Centre with your API key.

Australia Post - API Key

Enter your API key on the Australia Post Live Rates plugin configuraton screen at WooCommerce → Settings → Shipping → Australia Post Live Rates and hit the Save changes button at the bottom.