ARM template deployment to tenant level

PowerShell

function New-AzTenantDeployment {
    <#
        1/1/2020 - Kristian Nese
        In anticipation of updated SDKs, this function can be used to target ARM deployments to tenant scope
        
        .Synopsis
        Deploys Azure Resource Manager template to an Azure tenant

        .Example
        New-AzTenantDeployment -Name <name> -Location <location> -TemplateFile <path> -ParameterFile <path>
    #>

    [cmdletbinding()]
    param (
        [Parameter(Mandatory, ValueFromPipeline)]
        [ValidateNotNullOrEmpty()]
        [string] $TemplateFile,

        [string] $ParameterFile,

        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [string] $Name,

        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [string] $Location
    )
    begin {
        $currentContext = Get-AzContext
        $azureRmProfile = [Microsoft.Azure.Commands.Common.Authentication.Abstractions.AzureRmProfileProvider]::Instance.Profile
        $profileClient = [Microsoft.Azure.Commands.ResourceManager.Common.RMProfileClient]::new($azureRmProfile)
        $token = $profileClient.AcquireAccessToken($currentContext.Subscription.TenantId)
    }
    process {
        if(!([string]::IsNullOrEmpty($ParameterFile)))
        {
            $TemplateParameters = Get-Content -Raw $ParameterFile | ConvertFrom-Json
        }
        else 
        {
        $body = @"
{
    "properties": {
        "template": $(Get-Content -Raw $TemplateFile),
        "parameters": $($TemplateParameters.parameters | ConvertTo-Json -Depth 100),
        "mode": "incremental"
    },
    "location": $($Location | ConvertTo-Json -Depth 100)
}
"@

    # ARM Request
    $ARMRequest = @{
        Uri = "https://management.azure.com/providers/Microsoft.Resources/deployments/$($Name)?api-version=2019-08-01"
        Headers = @{
            Authorization = "Bearer $($token.AccessToken)"
            'Content-Type' = 'application/json'
        }
        Method = 'Put'
        Body = $body
        UseBasicParsing = $true
    }
    $Deploy = Invoke-WebRequest @ARMRequest
    #prettify
    [Newtonsoft.Json.Linq.JObject]::Parse($deploy.Content).ToString()
        }
    }
}