Run the signingclient list keys command to get the label of your code signing token.

$ signingclient list keys
Using token with label csaasdemo
Password:
Private Key Object; RSA 4096 bits
Label: csaasdemo
ID: 876057e0fe3b0d53c822c312f4a7c76a76dd5644
Usage: sign
 
Public Key Object; RSA 4096 bits
Label: csaasdemo
ID: 876057e0fe3b0d53c822c312f4a7c76a76dd5644
Usage: encrypt, verify, wrap

Your token might have more than one code signing key. Please make sure you select the right key.