Identify two prerequisites for configuring Enterprise Manager Database Express (EM Express).
A. Grant the APEX_PUBLIC_USER role to the SYSLIAN user.
B. Use the DBMS XDB CONFIG. SETHTTPPORT procedure to configure a port number for Oracle HTTP Server.
C. Install Oracle HTTP Server.
D. Configure at least one dispatcher for the TCP/IP protocol.
E. Create a SYSMAN user with the SYSDBA privilege as an administrator for EM Express.
BD
ref – https://docs.oracle.com/database/121/ADMQS/GUID-EB851101-07BE-4038-BB9D-06E01CC7F5D5.htm#ADMQS032
exec DBMS_XDB_CONFIG.SETHTTPSPORT(5500);
Enable the TCP dispatcher by adding the following entry to the init.ora file for the database you want to manage using EM Express:
dispatchers=”(PROTOCOL=TCP)(SERVICE=XDB)”
BD
https://community.oracle.com/community/support/support-blogs/database-support-blog/blog/2016/06/24/em-express-in-12c