Add VBA Macro and a button to run ot

Output: Vba.xlsx

public void Run()
{
    var workbook = new Workbook();
    var worksheet = workbook.Worksheets[0];

    var module = workbook.VbaProject.Modules["ThisWorkbook"];

    var codeBuilder = new StringBuilder();
    codeBuilder.AppendLine("Public Sub ShowIndexedColors()");
    codeBuilder.AppendLine();
    codeBuilder.AppendLine("Dim i As Integer");
    codeBuilder.AppendLine("Dim j As Integer");
    codeBuilder.AppendLine();
    codeBuilder.AppendLine("For i = 1 To 7");
    codeBuilder.AppendLine("\tFor j = 1 To 8");
    codeBuilder.AppendLine("\t\tCells(i, j).Value = 8 * (i - 1) + j");
    codeBuilder.AppendLine("\t\tCells(i, j).Interior.ColorIndex = 8 * (i - 1) + j");
    codeBuilder.AppendLine("\tNext j");
    codeBuilder.AppendLine("Next i");
    codeBuilder.AppendLine();
    codeBuilder.AppendLine("End Sub");
    module.Code = codeBuilder.ToString();

    var control = worksheet.FormControls.AddButton("Button 1", "A13");
    control.Size.WidthInches = 2.43;
    control.Size.HeightInches = 0.27;
    control.Position.XPixels = 5;
    control.Position.YPixels = 5;
    control.Macro = "[0]!ThisWorkbook.ShowIndexedColors";
    control.Text = "Show Indexed Colors";

    workbook.SaveAs("Vba.xlsm");
}