After migrating to Firebase, i tested sending notification by using the firebase console it works fine, but i need a daily notification on a specific time so instead of using th
I am not able to comment directly in the selected answer. Take in consideration that the json message changes according to what you want/need to receive in the recipient os (android/ios).
e.g for android to get the notifications when the app is in background you need to add the data json in your request.
For iOS the data key is not needed, but you must have the notification key along with isContentAvailble flag set to true and priority set to high.
In the selected answer as valid, you use registration_ids key should be only used when you are sending the notification to more than one device, maybe you should take a look to the topics notifications.