❔ Using mvvm toolkit- Why my view has no access to my command?

      [RelayCommand]
        public void CalculateAndSave()

And in the View:
<Window x:Class="Calculator.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:VM="clr-namespace:Calculator.ViewModels"
        xmlns:local="clr-namespace:Calculator"
        mc:Ignorable="d"
        Title="MainWindow" Height="525" Width="350">
    <Window.DataContext>
        <VM:CalculatorVM/>
    </Window.DataContext>