How to make a notification at top bar like facebook using angular2++ and firebase

Hello fellow StackOverflow community, I require your assistance here. I’m about to make a real time notification at top bar like facebook using angular v2 above with firebase integrate. I’d been successfully push the notification to my firebase account, and now I’m clueless how to display the content of what I’m pushed then into the HTML without require user to press F5 to reload the page itself

What I want is to make the notification subscribe the event of get-http using RXJS, event “@angular/router”, and lastly it will unsubsribe the event to make sure no memory leak. Please help me the community of StackOverflow guide me and teach me since I’m lost now

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