Aftership is a useful tool to rely upon when no direct carrier integration is possible. Thankful integrates with Aftership to track packages which are otherwise not available via an API. Success rates are much lower than a direct carrier integration, but it is better than nothing.
The carrier name for the Track Shipment step must
be in the format of aftership-{name}, where {name} is the name of the
carrier in question according to Aftership’s slug for this carrier. For
instance, “Asendia USA” would be aftership-asendia-usa because Aftership’s
defined slug is “asendia-usa”
here.
You can find your specific carrier in the Aftership documentation, then look for the slug in example JSON response body they provide.