Can a kind and patient Apple expert help a clueless one through the maze?

I know my way around Windows but am trying to help someone with a MacBook issue and neither of us understand a thing about Apple. The problem is that SBS IPTV on Kodi refuses to work though other channels work fine. Something I noticed while fumbling around is that connection permission requests sometimes pop up when trying to access a URL. For example, "application x wants to connect to url y on port 443". You are then given a number of options to proceed. One of the option combinations allows you to deny the request forever. I suspect, and would like to check, if this has accidentally happened with SBS, but I don't know how to access whatever produces this pop-up. Is this a firewall message? Any help would be much appreciated.