welcome Marton.
This might be part of what you want to do How do you create separate chat rooms? - #2 by SteveJG . Separate chat rooms with a CloudDB or a FirebaseDB intended for different topics are relatively simple to set up. 
. You just need to name each with a separate Tag and select from a list of topics.
If not, then please provide a more detailed explanation of what you want to do. We do not understand what you mean by "would allow me to associate a web address or the link of the chat wall." Could you provide an example?