When you ship an order, your customers will receive a link to track the order that includes the order ID and Order Key parameters taken from the WooCommerce order and allow us to identify the order to display the tracking information.
For example, a link we generate for order 12345:
https://yourstore.com/trackorder/order_id=12345&order_key=wc_order_12345
If anyone try to go directly to the tracking page, without the Order ID and Order Key in the URL parameters, they will be required to required to enter the order ID and the email address to view the tracking page.