You can use the MAKE_REQUEST and MAKE_REST_REQUEST procedures to enable Web Credentials in order to authenticate against the remote Web Service.

Web Credentials can be used with the APEX_WEB_SERVICE package from outside the context of an Oracle APEX application (such as from SQLcl or from a Database Scheduler job) as long as the database user making the call is mapped to an APEX workspace.

If the database user is mapped to multiple workspaces, you must first call APEX_UTIL.SET_WORKSPACE or APEX_UTIL.SET_SECURITY_GROUP_ID as in the following examples.

If the database user is mapped to multiple workspaces, you must first call APEX_UTIL.SET_WORKSPACE or APEX_UTIL.SET_SECURITY_GROUP_ID as in the following examples. The APEX_WEB_SERVICE package cannot be used by database users that are not mapped to any workspace unless they have been granted the role APEX_ADMINISTRATOR_ROLE.

apex_util.set_workspace(p_workspace => 'MY_WORKSPACE');

FOR c1 in (
   select workspace_id
     from apex_applications
    where application_id = 100 )
LOOP
   apex_util.set_security_group_id(p_security_group_id => c1.workspace_id);
END LOOP;