Modify Sensors with Powershell and PRTG API?

I have had a look at the page below and have been able to generate reports and list sensors however what I really want to do is modify sensor settings.

https://helpdesk.paessler.com/en/support/solutions/articles/68506-powershell-interface-for-prtg-api

Is it possible to do something like:

######ignore invalid SSL Certs##########
add-type @"
    using System.Net;
    using System.Security.Cryptography.X509Certificates;
    public class TrustAllCertsPolicy : ICertificatePolicy {
        public bool CheckValidationResult(
            ServicePoint srvPoint, X509Certificate certificate,
            WebRequest request, int certificateProblem) {
            return true;
        }
    }
"@
[System.Net.ServicePointManager]::CertificatePolicy = New-Object TrustAllCertsPolicy

######setup details, access related.
$auth = "username=user&passhash=hash"
$PRTGHost = "IPADDRESS"

function Set-prtgSensorProperty ([string]$SensorID,[string]$PropertyName,[string]$Value)
{
    $url = "https://$PRTGHost/api/setobjectproperty.htm?id=$SensorID&name=$PropertyName&value=$Value&$auth"
    $request = Invoke-WebRequest -Uri $url -MaximumRedirection 0 -ErrorAction Ignore


} # end function

Obviously I tried that and it didn't work but is there an alternative? Am I missing something?

# Ignore SSL errors
[System.Net.ServicePointManager]::ServerCertificateValidationCallback = {$true}

function Set-prtgSensorPropertyInherited ([string]$SensorID,[string]$PropertyName,[string]$Value)
{
    $url = "https://$PRTGHost/api/setobjectproperty.htm?id=$SensorID&name=$PropertyName_&value=$Value&$auth"
    $request = Invoke-WebRequest -Uri $url -MaximumRedirection 0 -ErrorAction Ignore


} # end function