Hi Jude Perera1,
Thank you for posting in the Microsoft Community Forums.
Make sure your device is connected to the Internet and that your network connection is stable.The Microsoft Authenticator app requires an Internet connection in order to receive and send authentication information.
Open the Microsoft Authenticator app and check that your Microsoft account is properly set up and associated.
Make sure you have enabled Notifications so that the app can send you authentication codes.
On your device, make sure you have granted notification permissions for the Microsoft Authenticator app.
If your account doesn't show up in the Microsoft Authenticator app or you suspect there's a problem with the settings, you can try removing the account from the app and adding it again.
Best regards
Neuvi Jiang