If you encounter the error message "Authentication failed" or "Security Data : UsernameToken authentication failed" while using the managed NetSuite plug-in, please check your payment processing profile in NetSuite to make sure you're using a valid REST key that was generated from the same merchant ID you are integrating to.

Additionally, make sure that the payment processing profile's TEST MODE setting corresponds with the environment of the key you're using. If your key was generated in the test environment, check the TEST MODE box. If your key was generated in the production environment, leave the TEST MODE box unchecked.

Additional Information

Where do I implement/update an API key using the managed plug-in for NetSuite?

How to Create a REST API Shared Secret Key