Your shipment can be listed in two different ways in DPD Shipper
Via Shipment List
If you click on the Shipment List button, it will look like this:
Click on the shipment you want to track. The details will be displayed on the right part of the screen. There you can click on the tracking link.
Via the Parcels grid
With this view, it will look like this:
Here you only have to click on the parcelnumber in the Parcel Number column:
If you gave your shipments a reference, you can track using that as well in both lists: