When attempting to void a PB Shipping API USPS return label, an error message similar to the following is displayed:
"Error message from PB Shipping API: XXXXXXXX ShipmentId or Tracking Number could not be found. USPSXXXXXXX could not be found."
The PB Shipping API USPS does not support voiding return labels.
This is an expected behavior because PB Shipping API USPS does not support voiding return labels.
If Scan Based Returns is enabled, then the account is only charged by USPS when the label is scanned, not when it is created. To enable Scan Based Returns, contact software support.
UPDATED: September 27, 2019