The DSC configuration still isn't known to Azure Automation. It's available on some local machines. It should be uploaded to Azure Automation DSC Configurations. Azure Automation provides the Import-AzureRMAutomationDscConfiguration cmdlet to import the configuration to Azure Automation:
Import-AzureRmAutomationDscConfiguration -SourcePath "C:\DSC\AA\DSCfiles\ConfigureSiteOnIIS.ps1" -ResourceGroupName "omsauto" -AutomationAccountName "datacenterautomation" -Published -Verbose
The DSC configuration on Azure after applying the configuration to the node should appear as follows:
