Monitoring vnet data gateway service and statistics

Hi mrflinstone 

I also couldn't find any documentation in regards Monitoring the Vnet however I can suggest to try this template

 https://learn.microsoft.com/en-us/data-integration/gateway/service-gateway-performance

If you can use the end point url of your Vnet and hopefully it has the same structure as the on pemises logs gateway. But I believe you can be able to build your own report with Power BI desktop if you can connect to the Vnet end point.