PL/SQL :: Add Consumer Group To System Plan

I am trying to write a SQL statement that will do the following:

2. Add the APPUSER consumer group to the SYSTEM_PLAN resource plan. Change the level 3 CPU resource allocation percentages: 60% for the APPUSER consumer group and 40% for the LOW_GROUP consumer group.

SQL>BEGIN
DBMS_RESOURCE_MANAGER.CREATE_SYSTEM_PLAN (SYSTEM_PLAN => ‘system_plan’,
CONSUMER_GROUP1 => ‘APPUSER’, GROUP1_CPU3 => 60,
CONSUMER_GROUP2 => ‘LOW_GROUP’, GROUP2_CPU3 => 40);
END;
/

When executing the statement, I get the following error message:

Error message:

ERROR at line 2:
ORA-06550: line 2, column 23:
PLS-00302: component 'CREATE_SYSTEM_PLAN' must be declared
ORA-06550: line 2, column 1:
PL/SQL: Statement ignored