If you want the build job to wait for the completion of a command workflow task, enter that task's ID. Typically the wait will be for an asynchronous command workflow task made earlier in the same build. In that case, the build step will generate the environment variable VCOMMANDER_WORKFLOW_TASK_ID, which can be used here.

You may also use environment variables in the text. Regular Jenkins syntax will be used to resolve the variables - either $xyz, ${xyz} or ${a.b} but not $a.b, while ignoring "$".