After you download the app to your mobile device, you should log in to it using the same credentials that you use for the web version of Business24 (username and password). An SMS key must also be issued for the login. You then choose whether you want to sign in to the app with a 6-digit PIN code or using biometric data (fingerprint identification is supported on Android devices and you can use Touch ID or Face ID on iOS devices).
Enter the PIN code or log in with your chosen form of biometric data. If your device does not recognize your fingerprint or facial image, you can use a PIN as a backup.