Hello @Sai Devaraj Manoharan ,
welcome to this moderated Azure community forum.
This blog post was submitted before Azure Managed Grafana was introduced.
As stated in the article, this managed version is highly recommended as a viable replacement over running your own VM, especially combined with Azure Data Explorer.
The VM I describe comes with a flaw regarding the Network Security Group.
If you still want to proceed with the VM, check if port 3000 is exposed to the outside world (TCP, any direction/destination.
Opening the port means you need to think about security. I would personally recommend (personal) Azure Bastion to access the VM nowadays.
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