//ui
<form action="" method='post'>
<img src="https://www.freeiconspng.com/uploads/no-image-icon-13.png" id="coverPreview" alt="">
<input type="file" id="cover" />
</form>
//css
input{
display:none;
}
//js
let coverPreview = document.getElementById('coverPreview');
let cover = document.getElementById('cover');
coverPreview.addEventListener('click',_=>cover.click());
cover.addEventListener("change",_=>{
let file = cover.files[0];
let reader = new FileReader();
reader.onload = function (){
coverPreview.src = reader.result;
}
reader.readAsDataURL(file);
});