In NetSuite, your API key for payment processing is applied to your payment processing profile.

The NetSuite bundle uses a REST shared secret key.

Navigate to your payment processing profile in NetSuite by going to Setup > Accounting > Payment Processing Profile.

To implement a REST API key, enter your REST key ID and REST secret key values in the REST Keys Configuration section of the profile and Save.

To use the Invoicing or Reporting integration, you will need to enter your REST API shared secret key values in your Invoicing and/or Reporting configuration pages in NetSuite. Please refer to the plug-in's documentation for more information on these.

Additional Information

How to Create a REST API Shared Secret Key