USPS Tracking Number in customer email

I currently am using Endicia for my USPS postage and it posts back the tracking number to the Shipment database once I ship a package.  I checked the database and the tracking number is getting stored there.

Then, when I complete the shipment I have an email being sent out to my customer using ShipmentSent.CustomerNotification message template.  The email is being sent and all the message tokens are being populated, except for %Shipment.TrackingNumber%

Any idea why this token isn't being populated with the tracking number?

BTW, I am using nopCommerce version 3.8

Thanks,
Dave

I think I found a couple of issues in the way I am trying to do it.  Endicia is trying to postback the tracking number before the shipment was created.  I can create the shipment, but then postback the data isn't included in the email.  I will have to play around with the order I am doing things...