Google Business Messages is down since July 31, 2024. Please read this article for more details: https://developers.google.com/business-communications/business-messages/resources/release-notes/update-on-gbm
To connect to Google Business Chat, you must be an admin of Google Workspace.
To integrate Google Business Chat, visit https://business-communications.cloud.google.com/. Create a partner account or use an existing one. Next, create an agent. Finally, copy the Brand ID and Agent ID to the integration settings.