OpenID allows you to use an existing account to sign in to multiple websites, without needing to create new passwords. More info on the official OpenID website.
When you specify callback URL in Okta settings use openidcallback file name. For instance, if your project resides at https://website.com/myproject, the callback URL will be https://website.com/myproject/openidcallback.
Security screen articles:
•CAPTCHA on authentication pages
See also: