[chrome extension] How to make image button on content script

chrome extension

create button script

const iconBtn = document.createElement('button');
const iconBtnUrl = URL;

iconBtn.setAttribute('id', 'iconbtn');
iconBtn.style.backgroundColor = 'transparent !important;';
iconBtn.style.padding = '0px';
iconBtn.style.borderWidth = '0px';
iconBtn.style.border = 'none';
iconBtn.style.position = 'absolute';
iconBtn.style.color = '#FFFFFF';
iconBtn.addEventListener('click', (e) => {
    // TODO
 }, false);
 
 iconBtn.innerHTML = '<img class="btn-img" src="'+ iconBtnUrl +'">';
 
document.body.appendChild(iconBtn);