This is an Early Access feature. To enable it, please contact Okta Support.
Settings > Customization
You can customize your Okta org by replacing the Okta domain name with a custom URL domain name that you specify. For example, if the URL of your Okta org is https://example.okta.com, you can configure a custom URL for the org such as https://id.example.com.
Okta uses CNAME DNS records to point to your Okta org. Because DNS does not allow you to set a CNAME record for a domain (for example, example.com), you must create CNAME records for subdomains (such asid.example.com).
Flush the cache
View configuration details
$ dig id.example.com