Patching ESXi hosts using Powercli script

I am trying to create a script to patch multiple ESXI hosts in a given file by uploading ESXi zip file to the datastore.
Please help me out on it.

$server= Get-Content "C:\temp\ESXi.csv"

$ESXi= $server| select Name

$hosts = $server| select -Last 1

$DS = get-vmhost $hosts| select -First 1 | Get-Datastore | Sort-Object CapacityGB | select Name, FreeSpaceGB, DatastoreBrowserPath -Last 1

$isosize = "40"  # ensuring datastore is having 10 times more free space.

$DSname = ($DS).Name

$DSpath = ($DS).DatastoreBrowserPath

$DS = ($DS).FreeSpaceGB

$Ds = [math]::Round($Ds)

if ($DS -gt $isosize){

    Write-Host -ForegroundColor Green Datatore: $DSname is having more than "40 GB" free space i.e $DS GB

     $source = "D:\ESXifile\ESXi6.7.zip"

     $filezip = "\ESXi6.7.zip"                       

     $fp = $DSpath + $filezip                          

     $result = Copy-DatastoreItem -Item $source -Destination $fp

    $v= get-vmhost $ESXi

    $v | Install-VMHostPatch -HostPath $fp