Install Playsms on raspberry

Hi

I install on my raspberry it follow this guide (but i use nginx for webserver)

https://help.playsms.org/en/installation/installation_using_install_script.html

but when i try both in local and remote it start with a download file.

Why?

Thanks in advance

DB

I update my configure with php 7.0 guide in playsmss blog.
Now when i lauch localhost/playsms system return 502 Bad Gateway error.