Select the Run Last Launched / Run command [ ] to re-launch the last configuration or launch the current selection in run mode. You can also use the keyboard shortcut Ctrl + F11
New in 3.3 is the ability to launch the selected resource. This feature shares the Run Last Launched command, so when it is enabled, it in effect replaces the Run Last Launched with the Run command.
The preference for launching last or launching the selected resource can be changed on the Run/Debug > Launching preference page.