如何将图像附加到特定位置的另一个元素上？

Question

Not sure if I worded my question well enough... here goes,

I am trying to re-create the behavior as shown in the image below:

Desired Result

I know how to make the panel slide in from the right, as shown here (except they come in from left): https://www.w3schools.com/howto/howto_js_curtain_menu.asp

So my question is, how would I affix the "X" close button??

Thanks for looking...

Ps. Here is the link to the curtain sliding in from the right: How to convert Slide from Left Curtain Menu , to Slide in From Right

Answer 1

Function call to hide naveBar.

function closeNav() {
    document.getElementById("myNav").style.width = "0%";
 }

Calling from:

<a href="javascript:void(0)" class="closebtn" onclick="closeNav()">&times;</a>