Problem with page numbers

[raimoh]

const fs = require('fs');
const docx = require('docx');

const { Document, Packer, Paragraph, Footer, TextRun, PageBreak, PageNumber, NumberFormat } = docx;

const doc = new Document({
	sections: [
		{
			properties: {
				page: { 
					pageNumbers: { start: 1, formatType: NumberFormat.DECIMAL }, 
				}, 
			},
			footers: {
				default: new Footer({
					children: [
						new Paragraph({
							text: PageNumber.CURRENT + ' of ' + PageNumber.TOTAL_PAGES
						}),
					]
				}),
			},
			children: [
				new Paragraph({
					children: [
						new TextRun('text on page 1'),
						new PageBreak(),
						new TextRun('text on page 2'),
						new PageBreak(),
						new TextRun('text on page 3')
					]
				})
			]
		}
	]
});

Packer.toBuffer(doc).then((buffer) => {
	fs.writeFileSync('doc.docx', buffer);
});

Hi!
I followed the readme to get page numbers, but the code above returns only a footer line saying "CURRENT of TOTAL_PAGES".
What am I doing wrong?
Thanks!