Go to Settings > Integrations and Keys, click New key, and search for ServiceNow. Select the item and click Continue.
In the Configure ServiceNow dialog, specify a key name and your ServiceNow Base URL, and click Save.
In the Integrations list, where your key is now included, click Authenticate..
Enter the API key received as described below and click Save.
Now that you've configured your integration, add one or more of the integration's actions to an automation, test the automation, and then add the automation to an incident type.