Create a new Authentication Scheme in Oracle APEX

Step 1:

Shared Components --> Security --> Authentication Schemes --> Create --> Based on a pre-configured scheme from the gallery

Step 2: Enter below details

Name: 

Name: Oracle SSO
Schema Type: HTTP Heade Variable

Settings:

Action if Username is Empty : Redirect to Bulit-in URL
Verify Username : Each Request
Logout URL of SSO Server : https://login.oracle.com/sso/logout

Step 3: Click on Authentication Scheme