Use the permissions router to define the permissions you want to grant to subscribers on channels or channel resources. You can set permissions on the channel and channel resource level. If you do not define permissions for a particular channel resource, that resource inherits the permissions of its parent channel.
Typically you use the permissions router in the realtime-permissions.js file in your site's backend to:
Note: Although it is recommended, you do not need to use the permissions router to set permissions. You can also define all your permissions logic in the realtime_check_permission()
function.