If you're looking to Download Speaker Intercom on your Chromebook laptop Then read the following guideline.

Use your phone to talk over Cast devices, Bluetooth speakers, speakers that support AirPlay, and other connected speakers. Once the app discovers a speaker, the user can select the speaker and use the Push-To-Talk button to transmit live audio to selected speakers. The app will discover any available Cast device connected to the same Wi-Fi network as the app. Be wary of feedback when sending audio to a nearby speaker, e.g. the phone's local speaker.