Different Auth Method.ps1

$scope = "https://graph.microsoft.com/.default"
$Tenants = @("tenant1.onmicrosoft.com", "tenant2.onmicrosoft.com", "tenant3.onmicrosoft.com") #List here your tenants
$AppID = "10f9be91-4c9b-4427-aa71-143d18abafb5" #Change this to your own app ID
$AppSecret = "vJctTjssIeidhuzNQDkfWUIF/Pe+ae+adfafafafaf" #Change this to your own App Secret

#Get device serial number
#$Serial = (Get-WmiObject -Class Win32_BIOS).SerialNumber

#Device Serial number, change this!
$Serial = "PC03SVKGXXX"

$authHeader = @{
	'Content-Type'  = 'application/x-www-form-urlencoded'
}

$authBody = @{
    'client_id'=$AppId        
    'grant_type'="client_credentials"
    'client_secret'="$AppSecret"
    'scope'= $scope 
}



foreach ($Tenant in $Tenants) {

    #Change token authority endpont
    $authority = "https://login.microsoftonline.com/$tenant/oauth2/v2.0/token"

    #Get Access Token
    $Request = Invoke-RestMethod -Headers $authHeader -Uri $authority -Body $authBody -Method POST
    $AuthToken = @{
        Authorization = "Bearer $($Request.access_token)"
    }

    Write-Host "checking from tenant : $Tenant" -ForegroundColor Yellow

    #URL for query autopilot device, always use filter, this moment only support contains as filter
    $url = "https://graph.microsoft.com/beta/deviceManagement/windowsAutopilotDeviceIdentities?`$filter=contains(serialNumber,'$Serial')"
    $AutopilotDevice = Invoke-RestMethod -Method Get -Uri $url -Headers $AuthToken -ErrorAction Continue
    if ($AutopilotDevice.'@odata.count' -eq "1")
    {
        write-host "found device serial $Serial in tenant $Tenant" -ForegroundColor Green
    }
}