Get-AZLogAnalyticsWorkSpace

# This PowerShell script will fetch the Log analytics workspace 

Set-ItemProperty -Path 'HKLM:\SOFTWARE\Wow6432Node\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord
Set-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord

Update the Application ID detials below to connect.
$Application_Id ="XXXXX-XXXXX-XXXXX-XXXXX"
$Tenant_Id= "XXXXX-XXXXX-XXXXX-XXXXX"
$Secret_Id = ConvertTo-SecureString "XXXXX-XXXXX-XXXXX-XXXXX" -AsPlainText -Force
$Credentials = New-Object System.Management.Automation.PSCredential($Application_Id , $Secret_Id)
Connect-AzAccount -Credential $Credentials -TenantId $Tenant_Id -ServicePrincipal 

#Update the subscription id
$SubscriptionID="XXXXX-XXXXX-XXXXX-XXXXX"
Select-AzSubscription -SubscriptionID $SubscriptionID

#Update the vm names in the text file
$Serverlist=Get-Content 'C:\Temp\vmlist.txt'

$All_workspace = Get-AzOperationalInsightsWorkspace
Foreach($Server in $Serverlist)
{ 
$VM_Object=Get-AZVM -Name $Server -WarningAction SilentlyContinue
$Extension_name = "MicrosoftMonitoringAgent"
$VM = Get-AzVMExtension -ResourceGroupName $VM_Object.ResourceGroupName -VMName $Server -Name $extension_name -ErrorAction SilentlyContinue
$Workspace_Id = ($vm.PublicSettings | ConvertFrom-Json).workspaceId
Foreach($Workspace in $All_workspace)
{
If($Workspace.CustomerId.Guid -eq $Workspace_id)
  { 
  Write-Output "the vm: $($Server) writes log to Log Analytics workspace named: $($Workspace.name)"
  "" | Select-Object @{N="Server";E={$Server}},@{N="WorkspaceName";E={($Workspace.name)}} | Export-CSV VM_WorkspaceName.csv -NoTypeInformation -Append
  }
}
}