You need https://getcomposer.org/doc/00-intro.md#locally to install dependencies. Once composer is installed, run composer install.
App requires an environment variable file (.env) with the variables:
APP_ROOT=/
GA=0
GAUA=UA-XXXXXXXX-X
endpoint=
If you have PHP in your system, you can run the built-in web server. E.g., php --server localhost:5000.
Open the URL http://localhost:5000/47d7wmjw and you should see a video embed, the title of the resource and other metadata requested from PNXS.