To start Oracle Enterprise Manager Database Express (EM Express) for a non-CDB, use the EM Express URL provided by Database Configuration Assistant (DBCA) when DBCA configured your non-CDB, as described in "Installing Oracle Database Software." That URL includes the HTTPS port number for the non-CDB.
If you do not know the HTTPS port number for the non-CDB, issue the following SQL statement in your non-CDB, and it returns the port that is configured for EM Express:
select dbms_xdb_config.gethttpsport() from dual;
If a port number is not returned by this statement, then you must manually configure an HTTPS port for this non-CDB, as described in "Configuring the HTTPS Port for EM Express."
See Also:
Oracle Database PL/SQL Packages and Types Reference for more information on the gethttpsport procedure