MSI with parameters

I am trying to upgrade some software using PowerShell and I am not sure if my parameters are correctly formatted .  See highlighted text

# Silent Install Secure Secure Authentication
# http://repository.eset.com/v1/com/eset/apps/business/esa/windows/v2/2.7.32.0/esa_nt64_enu.msi

# Path for the workdir
$workdir = "c:\scripts\"

# Check if work directory exists if not create it

If (Test-Path -Path $workdir -PathType Container)
{ Write-Host "$workdir already exists" -ForegroundColor Red}
ELSE
{ New-Item -Path $workdir  -ItemType directory }

# Download the installer

$source = "http://repository.eset.com/v1/com/eset/apps/business/esa/windows/v2/2.7.32.0/esa_nt64_enu.msi"
$destination = "$workdir\esa_nt64_enu_v2.msi"

# Check if Invoke-Webrequest exists otherwise execute WebClient

if (Get-Command 'Invoke-Webrequest')
{
     Invoke-WebRequest $source -OutFile $destination
}
else
{
    $WebClient = New-Object System.Net.WebClient
    $webclient.DownloadFile($source, $destination)
}

Invoke-WebRequest $source -OutFile $destination

# Start the installation

msiexec.exe /i "$workdir\esa_nt64_enu_v2.msi" ADDLOCAL="Credential_Provider" /qb /L*v "c:\esa_install_log.txt"

# Wait XX Seconds for the installation to finish

Start-Sleep -s 35

# Remove the installer

rm -Force $workdir\esa_nt64*