MainWindowViewModel.cs

using System.ComponentModel;

namespace WpfConnect
{
    public class MainWindowViewModel : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        private string _text = "Initial Value";
        public string Text
        {
            get => _text;
            set
            {
                if (_text != value)
                {
                    _text = value;
                    PropertyChanged.Invoke(this, new PropertyChangedEventArgs(nameof(Text)));
                }
            }
        }
    }
}