Answers for "document.body.append()"

how to appendChild in the begin of the div javascript

var element = document.getElementById("div1");
element.insertBefore(para, element.firstChild);

appendchild javascript

const parent = document.createElement('div');
const child = document.createElement('p');
const appendValue = parent.append(child);
console.log(appendValue) // undefined
const appendChildValue = parent.appendChild(child);
console.log(appendChildValue) // <p><p>