The operating system should never lock the screen on a computer that is running a Robotic Process Automation (RPA). For every computer or virtual machine that runs Robotic Process Automations, you must adjust the Windows registry to make sure the desktop or virtual machine never locks the screen. This includes turning off the use of screen savers.
Many applications are not designed to be used when the system is locked and could operate differently than the automation expects. Since RPA robots operate just like a user would, these robots require the same operating conditions a user would enjoy. If the automation does not involve user interaction, or if those applications can operate when the system is locked, then the automation should work fine.