You can share your creation either from the Editor or the Homepage
To share your creation from the editing page click Preview & Share > Continue.
After the file loads, the share options will appear.
If you're done personalizing your creation and have already left the editor, go to the My Creations tab in the upper toolbar of the homepage.
You can browse all your past creations and share any of them by clicking on Share, this will take you directly to the share options page.