You can add a tracking link to the customer account page so that your customers can track their orders there.

Here's what the account page looks like after you added a tracking link there.

Step 1
Go to your Shopify admin → Online Store → Themes → click Edit code from the Actions dropdown menu.

Step 2
Go to theme code files → find the customers/account.liquid file under the Templates folder.

Step 3
Under the line that reads:

<th id="ColumnFulfillment" scope="col" role="columnheader">{{ 'customer.orders.fulfillment_status' | t }}</th>

Add this code bellow:

<th> Track Order </th>

Step 4
Under the line that reads:

<td headers="RowOrder ColumnFulfillment" role="cell" data-label="{{ 'customer.orders.fulfillment_status' | t }}"> {{ order.fulfillment_status_label }}

Add this code bellow:

<td> <a href="{{shop.url}}/apps/parcelpanel?order={{ order.name | remove: "#" }}&token={{ order.email | split: "" | reverse | join: "" | replace: '@', '_-_' | url_encode }}" target="_new">Click here to get shipping updates</a></td>

Step 5
Save your changes.