Batch run test case in RQM

In test manager, I can run all test cases of a test plan at the same time.
In RQM, when I select only 1 test case (in test plan), I can click "Run Test Case" button.
But if I select 2 test cases, "Run Test Case" button will be disabled.
Is there any simple steps to run all or multiple test cases of a test plan?
Accepted answer

When you select a test case and choose "Run Test Case", you are actually prompted to pick or create a test case execution record to run. In other words, you run a TCER, not a test case. Obviously in this case you cannot run multiple test cases. If instead you go to the Test Case Execution Records section and select multiple TCERs, you will be able to run all the TCERs.