(function(){

const $container = document.querySelector('#site_container');

const example = () => {
    return new Promise(resolve => {
        setTimeout(() => {
            const $button = document.createElement('a');
            $button.href = '#';
            $button.innerText = 'EXAMPLE';
            resolve($button);
        }, 0);
    });
};

const handleClickButton = (evt) => {
    evt.preventDefault();
    console.log('Clicked');
}

const initApp = async () => {
    const $button = await example();
    $button.addEventListener('click', handleClickButton);
    $container.append($button);
};

initApp();

})();