Doubling up on Alexa: How to use multiple Amazon Echo devices together

The Amazon Echo got off to a flying start, establishing itself as one of the hottest smart home devices, assisted by the smaller Echo Dot, a capable sidekick that brings its connected skills in a smaller package. Amazon hasn't slowed, expanding its range of speakers - as well as the functions they offer.

Source : https://www.pocket-lint.com/how-to-use-multiple-amazon-echo-and-dots-setting-up-and-using-multiple-alexa-devices/