Jar file can be found in the repo /oreon.engine/Projekt.jar
In order to run execute command with java 11: java --module-path /path/to/javafx-sdk-11.0.2/lib --add-modules javafx.controls,javafx.fxml,javafx.base -jar Projekt.jar 
The .jar file needs to remain in the same relative location as the rest of the project structure as it uses contents of the res/ file.