Create one on one chat box instead of group chat

I am currently building a telehealth website with a chat function. However, my SendBird is set up as the default group chat. In the images below, users can either chat with other users or create a group chat. But I don’t want this functionality. I want users only to be able to chat with customer service or, if my medical provider contacts them, they can establish a chat room but not join other users. How can I implement this feature?

Also, I would like to enhance the mobile UI. My current UI is for desktop only and looks incongruent on mobile devices.

This is what I am using now
"import SendbirdApp from “@sendbird/uikit-react/App”;

Thank you