You're installing all of PHP itself? Oh. Well then.
When you said 'VPN' I assumed it was something that came entirely pre-configured. Any standard webhost would have changed a handful of default settings!
I'm used to using WAMP (Windows-Apache-MySQL-PHP), not LAMP(Linux version thereof) - (which seems to be what you have, given the console command you listed). However, in my install package for WAMP, there were several things that needed to be configured before several functions in this (and a few other scripts) would run. I know nothing about Linux commands, however.
First of all - Apache. You'll need to make sure mod_rewrite is enabled.
And then PHP.ini - turn on openssl. (Open up the file?? Remove the ; at the start of the line extension=php_openssl.dll to uncomment it and turn on openssl.) You'll also want to change the error_reporting to error_reporting = E_ALL & ~E_NOTICE & ~E_STRICT to remove some notices that an ordinary webhost would hide.
Ordinary people installing this script to a hosting provider wouldn't run into any issues, because these things are usually enabled as a best practice.