Once you've configured your Branded Tracking page in Shiptheory and enabled your carriers as required, your orders booked with these carriers will pass back a Shiptheory Branded Tracking Page URL. When customers click this tracking URL they will be directed to your Branded Tracking page to view the status of their order. This can be accessed via either clicking "Track" in the view shipment popup in Shiptheory, or by clicking the URL passed back to your channel. See more information on configuring your Branded Tracking here.
Depending on your channel configuration, your users may receive an email from your channel with this information, or you can provide it to them yourself, please Contact Support for any needed assistance with this. 
Please reach out if you have any questions from there!