Get tweets through azure

I am trying to replicate an example which I found in order to know a little about the azure operation. But I think I have a problem when using variables, to get the data that should be received.

The example is as follows: example link

The code they use in the example is:

runbook

param (
 [object]$WebhookData
 )

if ($WebhookData -ne $null) 
    {
        $BodyContent = $WebhookData.RequestBody
        Write-Output "There was a tweet from $BodyContent"
    }
else
    {
        Write-Error "Something went wrong buddy"   
    }

webhook

$Credential = Get-Credential

#Authenticate to Azure and AzureRM
Add-AzureAccount -Credential $Credential | Out-Null
Add-AzureRmAccount -Credential $Credential | Out-Null

#Provide the necessary information for your environment
$Webhook = New-AzureRmAutomationWebhook '
 -Name "TriggeredByTwitter"'
 -RunbookName "Hello-Twitter"'
 -IsEnabled 1 '
 -ExpiryTime (Get-Date).AddDays(10)'
 -ResourceGroupName "Automation"'
 -AutomationAccountName "AutomationAccount"

#Print the webhook uri
Write-Host $Webhook.WebhookUri -ForegroundColor Green

In my case I use the azure GUI to create the webhook , it makes me comfortable since I know practically nothing.