If so, can it work as an Alexa device?
I think this answers your question. Google is available to all and answers 90% of the questions asked here.
There was a project some time ago in the MagPi magazine that essentially did the listening for a trigger word, and only when it found this, did it activate the voice recognition on the corporate server to send the real trigger word.
Sorry I don't know what issue this was but it will give you something to search on.
@Hermesf Or search on 'can a Raspberry Pi be used in the Arduino cloud'
As far as Alexa I think the answer is yes, but the Arduino doc at
https://docs.arduino.cc/tutorials/projects/arduino-iot-cloud-amazon-alexa-integration/
is out of date at least with my Alexa app so I can't tell you the exact steps. Just use the Alexa app, it is usually quite easy to set up new routines.