First make sure you've read the README.md file completely, especially the "INSTALLATION AND CONFIGURATION" section. If it still doesn't work then you can:
Ask for help or submit a bug on Github (https://github.com/phpsysinfo/phpsysinfo/issues)
!! If you have any problems, please set DEBUG to true in phpsysinfo.ini
and include any error messages in your bug report / help request !!
If you have a great idea or want to help out, just create a pull request with your change proposal in the phpSysInfo repository.