I may have worded the question wrongly, I don't know how to put what I want to do in a simple statement.

At the right hand side of the attached image there is a red-colour message icon or component. This icon or component remains in the same location across most of the pages that the user navigates. It disappears only when the user clicks on it, in which case, it redirects the user to a chatroom. How do I use react to accomplish something like this? What is this called? I have difficulty searching how to do it on the internet because I don't even know what it is called. I can add such an icon or component manually on each of my webpage, but that seems to be too stressful. That Icon or component is situated at the same location regardless of the page being navigated