Configuration to Run Single Tests in Webstorm 18.3

How can set the configuration for running a single test within a spec file ?

The problem is that on one of our machines the "run single test" in the e2e spec files tries to run it as a karma test using the karma.conf in the project. The other system uses the protractor.conf (as expected).  (Run configurations for both cases are avaible)

There must be a way to configure whih configuration should be used, but we can't  find it in the settings.

Can someone explain how to set up the configuration for the single tests.