1. Registering a new PHP interpreter
A remote interpreter can be configured in a similar way as local ones. Through Project Settings | PHP, the PHP interpreter we want to use during development can be specified. This can be a local PHP installation, as well as a remote PHP executable. Clicking ... next to the selected interpreter will open a list of registered PHP interpreters. Click the green + to add a new Remote....
2. Selecting the remote PHP interpreter for the current PhpStorm project
Once a remote PHP interpreter has been registered and configured, we can set up our project to use it during development. Simply select it in the dropdown in Project Settings | PHP.
Once configured, all our Run/Debug configurations will make use of the configured PHP interpreter. Since we just configured a remote PHP interpreter as the one that should be used for our project, the following run configuration will always run on the remote server or Vagrant machine.
3. Using the remote PHP interpreter
Once configured, we can start using our remote PHP interpreter, for example for unit testing. Check the Running PHPUnit tests over SSH on a remote server with PhpStorm tutorial for more information.