I need to make required 4 textboxes in a WinForm, I am working with Visual Studio Code C#

Question

I can't start another private void since this one is already done:

private void InitializeComponent()
{
    label1 = new Label .....
    txtbx1 = new TextBox();
    txtbx1.Text = "";.....

    label2 = new Label .....
    txtbx2 = new TextBox();
    txtbx2.Text = "";.....
}

So basically what I need is to make required the fields on every textbox.

Can someone guide me please?