The Synchronization Actions are the following:
In ProcessRobot - Process Designer > ProcessRobot Actions > Enter/Exit Locked Region
In WinAutomation - Process Designer > Synchronization Actions > Lock/Release Handle
In general, the Locked Region's purpose is to ensure non-parallel execution of one or more Processes.
In order for the Locked Regions to perform correctly, they need to have the same name.
In the attached video the second Process cannot access the locked region until the first Process unlocks it.