Application Express Limitations in APEX Service

• Application authentication schemes not supported : LDAP, SSO, HTTP Header variable etc.

• OCI Web Application Firewall (WAF) service is not natively supported.

• Deployment of customer managed Oracle REST Data Services is not supported.

• Custom domain names are not natively supported.

• Oracle APEX runtime environment is not supported.

• Option to make a Service Request in Workspace Administration is DISABLED.

• Option to set SMTP parameters by using the APEX_INSTANCE_ADMIN package only.

• Limited support of procedures and functions for APEX_INSTANCE_ADMIN

• Disabled REST Administration interface, Workspace Purge Settings etc.

https://docs.oracle.com/en-us/iaas/apex/doc/apex-application-development-limitations.html