Bug. Cancel indicium does not work

The stamps.com plugin the cancel indicium does not work.  So it won’t  postage

It was a bug. We'll fix it.

Did you try to cancel sample label?

When I tried to cancel sample label I
Error. Label could not be found. This can happen if the label was never requested or if you are attempting to refund a sample label.


Enable Debugging on plugin configure page and try to cancel the label.
Send me plugin log file. I want to see the error message.