Disable Insert Sheet function - NOT Working

Hello - Disable Insert Sheet function - NOT Working... is this the correct code?

Private Sub Workbook_NewSheet(ByVal Sh As Object)
    With Application
        .DisplayAlerts = False
        .ScreenUpdating = False
    End With
    Sh.Delete
    With Application
        .DisplayAlerts = True
        .ScreenUpdating = True
    End With
    MsgBox "Adding Sheets has been disabled"
    
    Application.CommandBars("Ply").FindControl(, 945).Enabled = False
End Sub

John