Param
(
  [Parameter (Mandatory= $true)]
  [String] $upn,
  [Parameter (Mandatory= $true)]
  [String] $Location
)
#replace with your automation credential
$cred = Get-AutomationPSCredential -Name "Cred"
$Session = New-CsOnlineSession -Credential $cred
Import-PsSession $Session -AllowClobber -DisableNameChecking | Out-Null
#Number Allocation By Site add ones that relate to your form so that the system knows which area number to assign to the user
if($Location -ieq "UKREM"){
    $StartNumber = "441270"
} 
if($Location -ieq "UKHO"){
    $StartNumber = "440208"
}  
if($Location -ieq "UKPME"){
    $StartNumber = "44121"
} 
#Get Location ID
$LocationID = Get-CsOnlineLisLocation | Where {$_.Description -ieq $Location} | Select $LocationID
#Get Free Number
$MyNumber = Get-CsOnlineTelephoneNumber -InventoryType Subscriber -IsNotAssigned -TelephoneNumberStartsWith $StartNumber | Select -First 1
#Assign to User
$SetUser = Set-CsOnlineVoiceUser -Identity $upn -TelephoneNumber $MyNumber.Id -LocationID $LocationID.LocationID.GUID 
#Assign some more policies here
#Output
Get-PSSession | ? ComputerName -like "*lync*" | Remove-PsSession
$output = @()
$output += New-Object -TypeName psobject -Property @{upn = $upn; phone= "+$($MyNumber.Id)"}
Write-Output $output | ConvertTo-Json