DBMS_SCHEDULER External Job with credentials

To avoid scheduler error: ORA-27369: job of type EXECUTABLE failed with exit code: Permission denied make sure and add a credential to any DBMS_SCHEDULER job that is executing external code (e.g. shell script).

begin
sys.dbms_scheduler.create_job(job_name => 'URSCHEMA.URJOBNAME',
job_type => 'EXECUTABLE',
job_action => '/home/user/dir1/urshellscript.sh',
start_date => TRUNC(SYSDATE) + 12/24,
repeat_interval => 'Freq=Daily;Interval=1',
end_date => to_date(null),
job_class => 'DEFAULT_JOB_CLASS',
enabled => FALSE,
auto_drop => false,
comments => 'This job executes an external script');

dbms_scheduler.set_attribute('URSCHEMA.URJOBNAME', 'credential_name', 'OWNEROFCRED.CREDENTIALNM');

dbms_scheduler.enable('URSCHEMA.URJOBNAME');

end;
/