The user manual does not mention anything about speech to text. But you can just download a keyboard app such as Swype, as it includes speech to text feature.
HOW DO YOU TALK TO TEXT?
To talk to text, on the bottom left hand screen press and hold the 123 button, press change input method and then press google voice typing
To talk to text, tap on messenger, tap on the screen to "Enter Message", keyboard shows up. Tap on the microphone icon, to the left of the spacebar.
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