import 'package:password_input/password_input.dart';

class MyWidget extends StatelessWidget {
  Widget build(BuildContext context) {
    return Center(
      //Use this child anywhere in your app
      child: PasswordInputTextField(
        passwordLength: 6,
        keyboardType: TextInputType.text,
        autoFocus: true,
        inputFormatter: [
          FilteringTextInputFormatter.allow(RegExp(r'[a-zA-Z0-9_@.]'
              r''))
        ],
        textInputAction: TextInputAction.done,
        onSubmit: (password) {
          if (password == null || password.isEmpty || password.length > 6)
            setState(() {
              _errorMessage = "Enter Password";
            });
        },
      ),
    );
  }
}