Windows 10 not show keyboard

[samo92]

Hi, i've a touch screen and keyboard not appears when touch textfield/textformfield.

import 'package:flutter/material.dart';
import 'package:flutter_osk/flutter_osk.dart';

class SigninPage extends StatelessWidget {
  SigninPage({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        margin: const EdgeInsets.symmetric(vertical: 20, horizontal: 120),
        child: Card(
          child: Padding(
            padding: const EdgeInsets.all(12.0),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                TextField(
                  decoration: InputDecoration(
                      helperText: '',
                      labelText: 'Ingresa tu correo electronico'),
                ),
                Row(
                  children: [
                    Expanded(
                      child: TextFormField(
                        decoration: InputDecoration(
                            helperText: '', labelText: 'Ingresa tu nombre'),
                      ),
                    ),
                    SizedBox(width: 12),
                    Expanded(
                      child: TextFormField(
                        decoration: InputDecoration(
                            helperText: '', labelText: 'Ingresa tus apellidos'),
                      ),
                    ),
                  ],
                ),
                Row(
                  children: [
                    Expanded(
                      child: TextFormField(
                        decoration: InputDecoration(
                            helperText: '', labelText: 'Sucursal'),
                      ),
                    ),
                    SizedBox(width: 12),
                    Expanded(
                      child: TextFormField(
                        decoration: InputDecoration(
                            helperText: '', labelText: 'Empleado'),
                      ),
                    ),
                  ],
                ),
                Row(
                  mainAxisAlignment: MainAxisAlignment.end,
                  children: [
                    ElevatedButton(
                        child: Text('CANCELAR'),
                        onPressed: () => Navigator.pop(context)),
                    SizedBox(width: 20),
                    ElevatedButton(
                      child: Text('CREAR CUENTA'),
                      onPressed: () => WindowsOSK.show(),
                      //() => Navigator.pop(context),
                    )
                  ],
                )
              ],
            ),
          ),
        ),
      ),
    );
  }
}