powershell post to push/streaming dataset Unauthorized

Just started happening since sat april 23.

using the dataset' s generated powershell code example (user data replaced with XXX), no fails.

Invoke-RestMethod : The remote server returned an error: (401) Unauthorized.

$endpoint = "https://api.powerbi.com/beta/XXX/datasets/XXX/rows?key=XXX"
$payload = @{
"foo" =98.6
}
Invoke-RestMethod -Method Post -Uri "$endpoint" -Body (ConvertTo-Json @($payload))

not using auth, but the docs say its not needed.

Real-time streaming in Power BI - Power BI | Microsoft Docs