To use a VM lab, go the "Workspace section" of your part setting and select "VM lab" as the "Lab Type"
In the "Lab" section, all the labs that were configured by the org admin should be available for selection. Select the lab from the list -
Under the "Course Parameters" section of the Course Settings, the two applicable parameters for VM labs are -
Lab Session Length
This specifies the time for which the lab is launched. A lab can be ended earlier by a user by explicitly selecting "End Lab". Also, when the learner selects "Start Lab" in the middle of a session, the session is extended to the full value of "Lab Session Length" value.