powershell – Sharepoint Download file CSOM – last step

Ok, so this maybe more PowerShell related than SharePoint. Actually, I am looking for the last step of downloading a file:

Write-Host "Load file ..."
$file = $ctx.Web.GetFileByServerRelativeUrl($Source)

So, I have the $file object, that is a Microsoft.SharePoint.Client.ClientObject, how can I get it? I intentionally do not use PnP. Thank you.