How to get Client ID and Client Secret for Service Now Instance Oauth Authentication
Here are step-by-step instructions to get the ClientID and Secret from service now instance
1) Open your ServiceNow developer account at ServiceNow Developers and log in using your credentials.
2) Click on Start Building, and a new instance will open for you.
3) Search for "System OAuth" under All, and then click on Application Registry under System OAuth.
4) Click the New button in the top right corner.
5) Click on Create an OAuth API endpoint for external clients.
6) Fill in the Name and Redirect URL text boxes; other details such as Client ID and Client Secret will be generated automatically.
7) In the Redirect URL text box, enter: https://gcs.office.com/v1.0/admin/oauth/callback.
8) Click Submit
9) Navigate back to Application Registry, search for your secret name, and copy the Client ID and Client Secret.