HI @ciacformazione, @rupadhyaya, @bebang, @nikish @Erilsart,
Thanks for writing in.
@rupadhyaya, thank you so much for sharing us the solution by manually installing your Superfly through FTP.
The location of the extension can be found in your themeforest download files.
After downloading your could see the Superfly extension
Don't forget to update your setup to the latest version.
Let us know how it goes.