You can attach copy event to <span> element, use document.execCommand("copy") within event handler, set event.clipboardData to span .textContent with .setData() method of event.clipboardData
const span = document.querySelector("span");
span.onclick = function() {
document.execCommand("copy");
}
span.addEventListener("copy", function(event) {
event.preventDefault();
if (event.clipboardData) {
event.clipboardData.setData("text/plain", span.textContent);
console.log(event.clipboardData.getData("text"))
}
});<span>text</span>