Hi @Khanna Ji ,

Use OAuth 2.0 with SSO Integration

ServiceNow supports OAuth 2.0 for REST API authentication.
If your instance already uses SSO (SAML or OIDC), you can configure OAuth profiles tied to the same identity provider.
This way, the third-party tool can redirect users to your IdP for login. Obtain an access token for each user. Call ServiceNow APIs using that token.

API calls run under the user’s identity, so KB article ACLs apply automatically

Steps to Configure

Enable OAuth in ServiceNow

Go to System OAuth > Application Registry.
Create a new OAuth API Endpoint for External Clients.
Note the Client ID and Client Secret.

Configure Redirect URI. Set the third-party tool’s callback URL.