I added/changed Tracking Page design but I cannot see changes when I get link

If you have created multiple tracking pages, the first page created automatically becomes the Default

You probably edited the page, which is not the default. In this case, if you used Copy Tracking Page Link or Get Links in the Shipments section, you received links to the unchanged page by default. 

If you want to use this edited page, go to the Tracking Pages tab and use the Preview tracking page or Get Tracking Page Links concerning the desired page.

In addition, any tracking page can be made on the default page. To do this, go to Manage Workspace, select the desired workspace, and in its settings change the default page to the one you need. 

More details on how to change the default tracking page can be found in this article: How to Set a Tracking Page as Default

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