Google Cloud Platform and Wordpress - Permalink setting not working

We taught ourselves how to setup Wordpress on Google Cloud Platform. We have successfully created a VM instance, private key to FTP into Google Cloud Platform , pointed our our domain and learned how to create DNS Zones on Google Cloud Platform. The site is up and running. But now we have minor issue with permalink setting not working. When we set permalink to [login to view URL] the site works, we can navigate. But when we set the permalinks to Post Name [login to view URL] the site does not navigate the different pages. This is very minor issue.