Could the non-enrolled users be removed with powershell?

I have the following code:

$url = 'https://api-.....com/admin/v1/users'

$method = 'GET'

$date = (Get-Date).ToUniversalTime().ToString("ddd, dd MMM yyyy HH:mm:ss -0000").replace('.','')

$headers = @{
'Authorization'='Basic ...';
#'X-Duo-Date'='mi, 21 sep 2022 07:31:31 -0000';
'X-Duo-Date'=$date;
'Content-Type'='application/x-www-form-urlencoded'
}

iwr $url -Method $method -header $headers

clear-variable url,method,headers

{“code”: 40103, “message”: “Invalid signature in request credentials”,
“stat”: “FAIL”}

give me this code does anyone know what is happening?