Cannot "change" excel file

[astorDev]

I created the file helloWorld.xlsx, filled first row with "Hello".
Then executed the following:

using (var file = File.Open($"helloWorld.xlsx", FileMode.Open, FileAccess.ReadWrite))
{
    var workbook = WorkbookFactory.Create(file);
    var sheet = workbook[0];
    var helloCell = sheet.GetRow(0).GetCell(0);
    Console.WriteLine(helloCell.StringCellValue);
    var row = sheet.CreateRow(1);
    var worldCell = row.CreateCell(0);
    worldCell.SetCellValue("World"
    workbook.Write(file);
}

So after the execution I expect file to have two filled cells filled with "Hello" and "World", but in reality it stays as it was before the execution (With "Hello" only)