Please ensure you have enabled the biometric authentication functionality on your device to benefit from quick login to the app via fingerprint or Face ID.
For older versions of Android devices it can be enabled via 'Lock screen and Security' found in the 'Settings' menu, and for newer versions it can be enabled via 'Biometrics and Security' found in the 'Settings' menu.
For older version of iOS devices it can be enabled via 'Touch ID & Passcode' found in the 'Settings' menu, and for newer versions it can be enabled via 'Face ID and Passcode' found in the 'Settings' menu.