I notice that in FoxNews Facebook Messenger (https://www.messenger.com/t/FoxNews), when I click "Add Topic", the button text is changed to "Remove Topic", and vice versa.
Does anyone know how to do that?
To my knowledge, Facebook is testing new features and message templates with selected partners, so it may just take some more time until this feature becomes available to the general public. For example, the recently introduced List Template could already be seen on some larger media/news bot before it was officially announced and documented.