AutoVoice Autovoice not working in FireOS

I was trying the AutoVoice app for the first time in my Fire HD 8, I had installed Google services, Store bla bla, to be able to install android apps .So I was looking at a tutorial, so I created a profile, I select Autovoice as plugin, I enable the Autovoice Accessibility service but I don't know how to trigger the voice command? Is there a service missing to make it work? Has anybody make Autovoice work in a Fire tablet? Thanks in advance