SimpleLogin.xaml

<?xml version="1.0" encoding="UTF-8"?>
<ContentPage Title="Login" xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="MyProject.LoginPage">
  <Grid Padding="20" HorizontalOptions="CenterAndExpand" AutomationId="LoginPageIdentifier">
    <Entry AutomationId="FullNameTextField" Keyboard="Text" Text="{Binding Fullname}" />
    <Entry AutomationId="EmailTextField" Keyboard="Email" Text="{Binding Email}" />
      <Button AutomationId="SignInButton" Text="Send" Command="{Binding LoginCommand}" />
  </Grid>
</ContentPage>