00ufvw0mxOJZpbKrv351.5548183538928567E12 (Customer) asked a question.
I am looking for an article or blog which describe how to use Okta Event Hooks to trigger Security Alerts like User logged in from Unknown location, Suspicious activity on account or Admin activities like changing app username / create new sign-on policy etc

I haven't used Okta Event Hooks for this purpose but have used Okta's threatinsights feature to track and block logins from malicious IPs:
https://help.okta.com/en/prod/Content/Topics/Security/security-threat-insight.htm
Another way will be auditing the logs using Log APIs.