The situation is such that you need to implement a user notification that he does not have money in the account or other information for mandatory viewing. I often see this in cafes, you connect to wifi, and the phone immediately opens a window with a greeting and a request to enter a number. I understand that this hotspot, but how to emulate this situation? Those. There is a stub that notifies the subscriber that there is no money, but this is only in the browser.