I think you have a wrong understanding of how to call the index or a method of a controller. Please look at the documentation. https://laravel.com/docs/9.x/controllers#basic-controllers

Thanks for the reply cemarta7 but, I believe that once a session variable is loaded and its contents checked, the contents of the session variable must be visible everywhere in the program. I err?

This does not set the value dd(session('array_attivita'))

You need to do session(['key'=>'value'])

Take a look at the session storing methods in the documentation https://laravel.com/docs/9.x/session#storing-data

I realize I documented my question terrible. I'll do better next time. Thank you for your patience and replies. Good day. See you next time.