Explanation

The New-AzResourceGroup cmdlet creates an Azure resource group.
The New-AzAppServicePlan cmdlet creates an Azure App Service plan in a given location The New-AzWebApp cmdlet creates an Azure Web App in a given a resource group The New-AzWebAppSlot cmdlet creates an Azure Web App slot.
References:
https://docs.microsoft.com/en-us/powershell/module/az.resources/new-azresourcegroup?view=azps-2.3.2
https://docs.microsoft.com/en-us/powershell/module/az.websites/new-azappserviceplan?view=azps-2.3.2
https://docs.microsoft.com/en-us/powershell/module/az.websites/new-azwebapp?view=azps-2.3.2
https://docs.microsoft.com/en-us/powershell/module/az.websites/new-azwebappslot?view=azps-2.3.2