Google text to speech for asterisk

I installed Google text to speech for asterisk
it’s working fine!

I would now like to use it in my own way:
by an AMI call
example:

Action: Originate
Channel: SIP / 10
Application: playback
Extension: 10
Date: custom / msg-public-ref

I can then run an audio file after calling an extension

and if I wanted to reproduce text through text to speech ???

I tried with something like this:

Action: Originate
Channel: SIP / 10
Application: AGI
Extension: 10
Variable: intkey = BlaBalBla … | lang = it
Date: googletts.agi

not by mistakes but it does not work either

thanks for help

Evolution

Action: AGI
ActionID: 123456
Channel: SIP / 10
Command: (googletts.agi, “Google text to speech for Asterisk”, en)
CommandID: 345678

but by mistake I say I do not have the permissions