If you are looking for a way for "admins" send messages to "members", then using third-party tools such as Intercom and Drift, you can easily make that possible.
All you would need to do is to get the script from the chat software and simply add it to your community Admin Panel> Theme> Advanced Setting> <body> tag or , head> tag (it depends on the chat software you are working with).
We also offer a native integration with Intercom that helps you get more than just the messenger box. You can learn more here35.
But, if you want regular users to chat and send messages to one another, you can install the "Messages" app from the Admin Panel> App section.
Please click here8 to learn more about this option.