How to create a NetSuite Application ID
Login to your NetSuite account.
Click on Setup -> Integrations -> Manage Integrations -> New
On the resulting page, Name the application that will be integrating with NetSuite (for example, "LW") Make sure the "Token Based Authentication" is unchecked and only the "User Authentication" is checked
Press Save. On the resulting page, the Application ID will be generated for the application
Copy the Application ID and provide it to your support engineer or paste it into an email to firstname.lastname@example.org and be sure to include your company name so we can be sure to add it to the correct organization.