By default, the system has a notification system that will load notifications after reload. if you want to make it real-time you need to set up pusher credentials. you can create here free account pusher.com.
.env file pusher section.
PUSHER_API_KEY=api_key PUSHER_APP_ID=app_id PUSHER_APP_KEY=app_key PUSHER_APP_SECRET=app_secrete PUSHER_APP_CLUSTER=ap2 MIX_PUSHER_APP_KEY="${PUSHER_APP_KEY}" MIX_PUSHER_APP_CLUSTER="${PUSHER_APP_CLUSTER}"
Note: Don’t forget to enable real-time notification from the admin settings.