Non-nullable instance field 'user' must be initialized. Try adding an initializer expression, or a generative constructor that initializes it, or mark it

[vedantbahel]

I tried implementing the same but it gives me error:
"Non-nullable instance field 'user' must be initialized.
Try adding an initializer expression, or a generative constructor that initializes it, or mark it"

for

User user;
Timer timer;

And if I further do

User? user;
Timer? timer;

then it throw exception
No implementation found for method Auth#registerIdTokenListener on channel plugins.flutter.io/firebase_auth

[mebo1yt]

you must add late because you will give this a value later

late User user;
late Timer timer;