Debian Official Live DVD and Orca problem

[Egon <cvimail81@gmail.com>]

Hi All!

I want to try the Debian Live system with Orca but Orca do not start 
when I press altGr-s combination when the system is loaded. I tried to 
press the left Alt-key too.
I visited Debian Accessibility Wiki.
I pressed altGr-s when the system boots up but Orca did not start.
Pressing Alt-F2 and typed orca command, it starts, but it speaks only in 
that window and did not read any information. :-(
I downloaded Debian Official Live DVD from here:
https://cdimage.debian.org/debian-cd/current-live/amd64/iso-hybrid/
I tried Gnome and Mate environment, the situation is the same. :-(

I asked help from my friend who has no visual problem, she unable to 
find Orca in the system menu to start it.

What can I do?

Best regards: Egon