From your post I see that you dont know where playsmsd and /etc/playsmsd.conf, they are described in the article. And, your PHP is not configured properly, this is not good, and I think you need to shut the VM down for now. If possible just create a new one, or rebuild it.
Better learn how to do it locally on VirtualBox first, and when you know what to do and ready you can then install on cloud.
Please try first on VirtualBox, follow this article:
Btw, the manual is in Ubuntu 18.04, I’m not sure if its the same in Debian 9. You can try it on VirtualBox.