Alexa will join the meeting and pass the name associated with the Alexa account, to Zoom. Customers can also sign-in to their Zoom account on the Echo Show 8 to have a full Zoom account functionality. To sign-in to your Zoom account simply say “Alexa, open Zoom.” The app will open on the device allowing you to sign-in.
https://aws.amazon.com/about-aws/whats-new/2020/12/join-zoom-meetings-with-alexa-on-echo-show-8/