The Webserver that you use to control Kodi is build in and can not be used for external tools.
So you would need Apache (or another Webserver). But if you install a Webserver watch out that you either change the port of the internal Kodi Webserver or the one you install.
Your Debian how to should quite well work on OSMC.
Actually you can check [TESTING] LAMP stack on OSMC for a full LAMP install