JSFiddle - React, Tailwind, and code Playground

HTML

<pre id="out"></pre>

JavaScript

const obj = {className: 'test', id: 'item_42'}

let str = `<ul class="{{ className }}" id="{{ id }}"></ul>`

for (let key in obj ) {
    const re = new RegExp(key, 'g');
    str = str.replace(re, obj[key]);
}

out.textContent += '\n' + str;