In each of the directories in this repository there will be a README.md that contains a link to deploy that template to Azure. You will need to fill in the form, once launched in the Azure Portal, with the proper values (e.g. number of compute nodes).
Currently there are templates for Unbuntu 16.04 LTS and CentOS 7.4.
Simply SSH to the master node as the azureuser and with the password you gave and do a srun or sbatch submission! The DNS name is generated by the template and returned as a template output that can be viewed in the portal or by looking at the deployment outputs.
Authentication is either via the hardcoded username/password, or via Azure AD