Android Flutter Debug - Device Not Authorized

On your device, go to Developer options-->Revoke USB Debugging and Disconnect your device. After reconnecting, you will get a RSA Fingerprint verification window, click on accept. Done..

According to Eefret - on Stack OverFlow, it's was a problem with the certificate dialog on Android device at the moment of the connect

The problem on Intellij was the same of the Android Studio, and this question fixed the problem:

Android Studio - ADB Error - "...device unauthorized. Please check the confirmation dialog on your device."