Using Azure Yaml pipeline to call powershell RestMethod with secret variable in body - azure

Question

I am trying to automate a step in our Azure yaml pipeline to delete some users from Auth0 using PowerShell and RestMethod, but for some reason the secret is either not used correctly or changed or something.
I have set the secret as a variable and then tried using it either directly in the script or through setting it on the task as well as an environment variable, but no luck.
Here is my last iteration, but still no joy, could anyone shed some light on the issue?
$api = "api/v2/"
$audience = $audience + $api
$secret = "$env:AUTH0_CLIENT_SECRET"
$test = [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes($secret))
Write-Host $clientSecret.substring(0,10)
Write-Host $test.substring(0,10)
Write-Host $audience
Write-Host $clientId
$Body = #{
client_id = $clientId
client_secret = $test OR $secret OR $clientSecret
audience = $audience
grant_type = "client_credentials"
}
Write-Host 'Getting token'
$response = Invoke-RestMethod https://mytenant.eu.auth0.com/oauth/token `
-Method 'POST' `
-ContentType 'application/json; charset=utf-8' `
-Body ($Body | ConvertTo-Json)
As shown, I have tried using test, secret and clientSecret as the secret, but also no luck. The write host at the start does show the correct starting characters for $clientSecret
Am I missing something basic or is this just not possible using RestMethod?

Answer 1

Ended up going scorched earth and completely deleted the pipelines and started again, this is the powershell script I ended up with that worked.
$token = "/oauth/token"
$https = "https://"
$api = "/api/v2/"
$audience = $https + $domain + $api
$tokenUrl = $https + $domain + $token
Write-Host 'Getting token'
$response = Invoke-RestMethod $tokenUrl `
-Method 'POST' `
-ContentType 'application/json; charset=utf-8' `
-Body (#{
client_id = $clientId
client_secret = "$env:AUTH0_CLIENT_SECRET"
audience = $audience
grant_type = "client_credentials"
} | ConvertTo-Json)