Now I remember! But wasn't there something with echo that had to be constantly updated using a rasberry pi for this to work?
Not with Echo Speaks (if you use Heroku).
With AlexaTTS, you can either renew the cookie manually every two weeks, or setup a Nodejs app on an RPi (or equivalent) to do it for you. In both cases, there's no manual intervention needed after initial setup.
Ok. Thanks for clarifying.