The described functionality is handled by the Google App Engine Support for PHP plugin. The plugin is no longer maintained and is incompatible with IntelliJ IDEA starting from version 2018.1.
Install the PHP plugin
This functionality relies on the PHP plugin, which you need to install and enable.
note
The PHP plugin is available only in IntelliJ IDEA Ultimate.
Press CtrlAlt0S to open the IDE settings and select Plugins.
Open the Marketplace tab, find the PHP plugin, and click Install (restart the IDE if prompted).
With IntelliJ IDEA, you can develop a PHP application for running in the Google PHP Runtime Environment. IntelliJ IDEA supports all the major Google App Engine for PHP development practices and provides the possibility to run and debug your applications locally before uploading them to the runtime environment.
Google App Engine support in IntelliJ IDEA
A dedicated project type with a specific directory structure and configuration file.
A dedicated App Engine for PHP run/debug configuration for running and debugging applications on the PHP Development Server which comes bundled with the Google App Engine for PHP SDK.
Uploading applications using the command of the Tools menu.