To control an Amazon Fire Stick with a remote control, enable HDMI CEC on your TV before you connect the Fire Stick to the TV’s HDMI port
Without this the remote won't work.
And i belive they're is a similar setting in firestick too, can remember clearly..
To setup properly just install the android fire tv remote app on your phone, Connevt to firestick and you can setup everything.. If you ate comfortable using phone to navigate then this app is all you need,
Here us the link
Simple navigation, a keyboard, plus voice search for Fire TV.
play.google.com