Project Launcher not signing APK

How i generate a file to upload in web browser with this method? I tried, but just opened the web browser to test it.
I don´t get it.

I´ve configured the package way to build. But when i hit the “Launcher” button in ProjectLauncher window, looks like my configuration i made don´t work. Can you explain how does it work and how i do to launch properly, creating an APK file.
Thanks