I haven't used the new HTML5 edition of SGDK2, but in the previous version, there was a "Generate Project" button. You would go into the folder where your project was in, and look into another folder that had the same name as your project
Directory "SuperHamster"
SuperHamster.sgdk2
SuperHamster (Folder) <- This
Then search for SuperHamster.exe
And that was your EXE.
But if this doesn't help, there were probably some changes that made this method obselete. Welcome to the community, by the way! It's awesome to see new people use SGDK2, can't wait to see what you will make and contribute.