Carrier Calculated Shipping must be enabled for your store to access and display Sendle shipping rates.

To be eligible, your shopify plan must meet one of the following requirements:
1. It is on the Advanced Shopify plan or higher.
2. Your Shopify plan is changed to paid annually.
3. On any plan request Carrier shipping upgrade for $20 per month.

Once one of the above is true, please contact shopify support who will enable it immediately when requested.

After that go to the following link and install the app
https://apps.shopify.com/AustraliaPostShipping
1. After installing it go the admin-> app -> AustraliaPostShipping

2. Then you can see the home page of the app. here you can see 4 section. First one for “Carrier Calculated” service status. Second one for account management. Here you have add mypost account to get shipping quote and book shipment to fulfil orders. Third for manage orders. here you can see a list of orders to see shipping quote and book shipment. Here you can also see a link to synchronise last 60 day’s orders. Forth for manage product dimension. Here you can update your shopify product dimension and also you can also see a link to synchronise shopify products with our app.