Traditional MVVM implementation. See: https://medium.com/@worldbeater/reactive-mvvm-for-net-platform-175dc69cfc82

ViewModel.cs

public class ViewModel : INotifyPropertyChanged
{
    public ViewModel()
    {
        Clear = new Command(() => Name = string.Empty);
    }
    
    public ICommand Clear { get; }
    
    public string Greeting => $"Hello, {Name}!";

    private string name = string.Empty;
    public string Name
    {
        get => name;
        set
        {
            if (name == value) return;
            name = value;
            OnPropertyChanged(nameof(Name));     // Raise the event for "Name"
            OnPropertyChanged(nameof(Greeting)); // Raise the event for "Greeting"
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}