$resoucegname = $ret[0].Name
$body = '{
  "resources": [
    "*"
  ],
  "options": "IncludeParameterDefaultValue,IncludeComments"
}'
$requesturi = "https://management.azure.com/subscriptions/$subscriptionid/resourcegroups/$resoucegname/exportTemplate?api-version=2021-04-01"
$ret = (Invoke-WebRequest -Uri $requesturi -Headers $headers -Method Post -Body $body)
$ret
$requesturi = $ret.Headers.Location