https://blog.gpunktschmitz.com/504-powershell-download-file-from-server-via-https-which-has-a-self-signed-certificate/ - это на Powershell 5 не сработало

"[System.Net.ServicePointManager]::ServerCertificateValidationCallback = {$true};(New-Object Net.WebClient).DownloadString(\"127.0.0.1/xxx\")"