setInterval(addLabelToAds, 1000);

function addLabelToAds() {

    Array.from(document.querySelectorAll('.ad-pos-label')).forEach( x => {
       x.parentNode.removeChild(x);
    });

    Array.from(document.querySelectorAll("[id^='gpt-slot']")).forEach(x => {
        var id = x.id;
        var pos = x.getAttribute('class');
        var el = document.createElement('div');
        el.setAttribute('class', 'ad-pos-label')
        el.setAttribute('style' , 'font-size: 50px; font-family: sans-serif; z-index: 100000; color: #fff; background-color: blue; position: relative; min-width: 100px; left: 0; top: 0;');
        el.innerText = `${pos}`;
        x.appendChild(el)
    });

}