If you are reading this page then you didn't add a value for the RepoFolder parameter
Try one of these commands:
Out of Box Experience Start-OSDPadRepo OOBE
OSDCloud Setup Start-OSDPadRepo OSDCloudSetup
Edit-OSDCloud.winpe Start-OSDPadRepo OSDCloudWinPE
OSDCloud Deployment Samples Start-OSDPadRepo OSDCloudDeploy
OSDCloud Deployment Task Sequences Start-OSDPadRepo OSDCloudTasks