Formatting table header with vertical text

[twimsatt]

I am attempting to format headers for a table so that they are vertical rather than horizontal and nothing seems to work:
let pptx = new PptxGenJS();

// Simple Slide
window.doDemo = function do7cells() {
let pptx = new PptxGenJS();
let slide = pptx.addSlide();
let opts = {
x: 0.0,
y: 0.25,
w: '100%',
h: 1.5,
align: 'center',
fontSize: 24,
color: '0088CC',
fill: 'F1F1F1'
};
slide.addText(
'BONJOUR - CIAO - GUTEN TAG - HELLO - HOLA - NAMASTE - OLÀ - ZDRAS-TVUY-TE - こんにちは - 你好',
opts
);
let arrObjText = [
{ text: "Red ", options: { color: "FF0000" } },
{ text: "Green ", options: { color: "00FF00" } },
{ text: "Blue", options: { color: "0000FF" } },
];
slide.addText(arrObjText, {
x: 0.5,
y: 2.0,
w: 9,
h: 1,
margin: 0.1,
fill: "232323",
rotate: 270
});

let arrTabRows = [
[
    { text: "Cell 1 A", options: { fontFace: "Arial" } },
    { text: "Cell 1 B", options: { fontFace: "Courier" } },
    { text: arrObjText, options: { fill: "232323", rotate: 270 } },
],
];

slide.addTable(arrTabRows, { x: 0.5, y: 3.5, w: 9, h: 1, colW: [1.5, 1.5, 6] });

pptx.writeFile();
}