For the original template, go to https://github.com/AlmasB/FXGL-MavenGradle
Open gradle Window:
View -> Window Tools -> Gradle
In window -> Tasks -> Application -> run
if maven is not available on your right side build tab, right click on pom.xml
and click on "add as maven project"
after that, click Configurations and "Edit Configurations..."
then add new config:
and add command line parameter for javafx: