There are a few steps that are needed before setting up the actual Integration record
Enabling required NetSuite feature
Make sure that all features are enabled by navigating to Setup > Company > Enable Features. Under the SuiteCloud subtab, find the Manage Authentication field group and enable the Token-Based Authentication and OAuth 2.0 features.

Set up a custom integration-specific role
- Navigate to Setup > Users/Roles > Manage Roles > New
- Give the role a descriptive name and ID, making it clear to other users what the role is used for.
- Set the necessary permissions, restrictions, and preferences needed for your Integration to properly function.
Set up a custom Integration-specific Employee
- Navigate to Lists > Employees > Employees > New
- Give the Employee a descriptive name and ID, making it clear to other users what the Employee is used for.
- Under the Access subtab, assign the newly created Integration Role.
Integration Record creation
- Navigate to Setup> Integration > Manage Integrations > New
- Give a descriptive name, description and necessary details.
- Enable necessary features in Authentication tab

Upon save of the Integration record, NetSuite will generate the Consumer ID and Consumer Key values.
NOTE: These will only be displayed once for security purposes.