Unable to ingest JSON stream data to Azure Event Hub - powershell

Question

I would like to post the JSON results which I am getting from an API endpoint to the Azure Event Hub $default consumer group but I am getting the below error:
Invoke-RestMethod : The remote server returned an error: (401) Unauthorized.
At H:\Users\User1 - scripts\get_mel_streetparking_data.ps1:34 char:1
+ Invoke-RestMethod -Uri $URI -Method $method -Headers $headers -Body $res ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (System.Net.HttpWebRequest:HttpWebRequest) [Invoke- RestMethod], WebException
+ FullyQualifiedErrorId : WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeRestMethodCommand
I wrote the below piece of powershell script where the following piece of get code runs fine:
$url = "https://data.melbourne.vic.gov.au/resource/vh2v-4nfs"
$apptoken = "abcdasdadaaf"
# Set header to accept JSON
$headers = New-Object "System.Collections.Generic.Dictionary[[String],[String]]"
$headers.Add("Accept","application/json")
$headers.Add("X-App-Token",$apptoken)
$results = Invoke-RestMethod -Uri $url -Method get -Headers $headers
but below piece of code fails with the above given error:
$method = "POST"
$URI = "https://[servicebusNamespace].servicebus.windows.net/[eventHubPath]/messages"
$signature = "SharedAccessSignature sr=[servicebusNamespace].servicebus.windows.net%2feventhub- streetparking&sig=%3dgZfDHEGN8lVEGgqu4N64TW70BLuSKARSKgMPeRByc%5d&se=604985&skn=RootManageSharedAccessKe"
# API headers
$headers = #{
"Authorization"=$signature;
"Content-Type"="application/json";
}
# create Request Body
#$body = "$results"
# execute the Azure REST API
Invoke-RestMethod -Uri $URI -Method $method -Headers $headers -Body $results
I generated SAS token with the help of the below code:
[Reflection.Assembly]::LoadWithPartialName("System.Web")| out-null
$URI="[servicebusNamespace].servicebus.windows.net/[eventHubPath]"
$Access_Policy_Name="RootManageSharedAccessKey"
$Access_Policy_Key="Root key value"
#Token expires now+3000
$Expires=([DateTimeOffset]::Now.ToUnixTimeSeconds())+3000
$SignatureString=[System.Web.HttpUtility]::UrlEncode($URI)+ "`n" + [string]$Expires
$HMAC = New-Object System.Security.Cryptography.HMACSHA256
$HMAC.key = [Text.Encoding]::ASCII.GetBytes($Access_Policy_Key)
$Signature = $HMAC.ComputeHash([Text.Encoding]::ASCII.GetBytes($SignatureString))
$Signature = [Convert]::ToBase64String($Signature)
$SASToken = "SharedAccessSignature sr=" + [System.Web.HttpUtility]::UrlEncode($URI) + "&sig=" + [System.Web.HttpUtility]::UrlEncode($Signature) + "&se=" + $Expires + "&skn=" + $Access_Policy_Name
$SASToken
Please help me why am I seeing unauthorized error

Answer 1

It was my bad that I did not replace the below values before the SAS token generation.
$Access_Policy_Name="RootManageSharedAccessKey"
$Access_Policy_Key="Root key value"