The Azure Marketplace deploys Elasticsearch onto Ubuntu VMs, so you'll need an ssh client to log in. You can use Azure cloud shell with Bash if you don't have an ssh client on your machine.
You'll need to ssh into Kibana VM using the admin username and password/ssh key that was specified in step of the Azure Marketplace portal:
In the shell
ssh <admin username>@<kibana public IP address>
Take a look at the accessing nodes documentation for more details. Once connected to the Kibana VM, you'll can then access the files, ssh into another VM on the network, etc.