JSFiddle - React, Tailwind, and code Playground

JavaScript

let pdfInvoice_sub_template = [
		{text: '{i}', alignment: 'center'},
		{text: 'invoices_sub-{i}-name', alignment: 'left'},
		{text: 'invoices_sub-{i}-unit', alignment: 'center'},
		{text: 'invoices_sub-{i}-amount', alignment: 'center'},
		{text: 'invoices_sub-{i}-price_wo_vat', alignment: 'center'},
		{text: 'invoices_sub-{i}-sum_wo_vat', alignment: 'center'},
		{text: 'invoices_sub-{i}-vat_type', alignment: 'center'},
		{text: 'invoices_sub-{i}-sum_vat', alignment: 'center'}
	];
this_pdfSubTemplate = [];

for (i = 1; i <= 2; i++) {
		this_pdfSubTemplate[i] = pdfInvoice_sub_template;
		jQuery.each(this_pdfSubTemplate[i], function (key, val) {
				console.log(val.text = val.text.replace(/{i}/g, i));
		});
}