Connecting to VM from Azure Automation Runbook

You can absolutely automate processes inside your network with Azure Automation. But you cannot use the sandbox approach. By "sandbox" a mean using the default cloud workers. What you need is a Hybrid Worker, i.e., a worker that runs your runbooks from your own VMs (either on-premises or in your Azure VNet). Please, see the documentation below:

https://docs.microsoft.com/en-us/azure/automation/automation-hybrid-runbook-worker