Powershell -UseDefaultCredentials to Authenticate URL - powershell

Question

New to the forum and new to Powershell. Hopefully in the right place. I'm trying to authenticate a web url and use the -UseDefaultCredentials within Powershell. I found this code on Stackoverflow - 404 Response:
$URI='http://www.example.com'
try {
$HttpWebResponse = $null;
$HttpWebRequest = [System.Net.HttpWebRequest]::Create("$URI");
$HttpWebResponse = $HttpWebRequest.GetResponse();
if ($HttpWebResponse) {
Write-Host -Object $HttpWebResponse.StatusCode.value__;
Write-Host -Object $HttpWebResponse.GetResponseHeader("X-Detailed-Error");
}
}
catch {
$ErrorMessage = $Error[0].Exception.ErrorRecord.Exception.Message;
$Matched = ($ErrorMessage -match '[0-9]{3}')
if ($Matched) {
Write-Host -Object ('HTTP status code was {0} ({1})' -f $HttpStatusCode, $matches.0);
}
else {
Write-Host -Object $ErrorMessage;
}
$HttpWebResponse = $Error[0].Exception.InnerException.Response;
$HttpWebResponse.GetResponseHeader("X-Detailed-Error");
}
The code above is doing what I want with returning the HTTP code. However, the question is, where do I insert the -UseDefaultCredentials within this block of code? I've tried adding it in to within and outside the try statement but get the error message:
Error Message
I originally used this piece of code:
Invoke-WebRequest -Uri http://www.example.com -UseDefaultCredentials
but my problem I experienced was then trying to write out the HTTP return code compared to the code that is listed above.
Any help would be appreciated.