NavigateTest/AvaloniaApplication1/Navigate.cs

using Avalonia.Controls;
using AvaloniaApplication1.Views;
using AvaloniaApplication1.ViewModels;
using ReactiveUI;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AvaloniaApplication1
{
    public class Navigate : ReactiveObject
    {
        UserControl view = new Auth();
        public UserControl View
        {
            get => view;
            set => this.RaiseAndSetIfChanged(ref view, value);
        }     
    }
}