How to overlay and move elements on an image?

Question

css

Good day. There is a desire to make another service of dynamic covers in VK. There are no problems with the server part - the problem is with the creation of the editor of this cover. The essence is something like this:
1. The user presses the "Upload image" button.
1.1 The image is loaded immediately without refreshing the page.
2. The user clicks on one of the buttons that creates an element on the image that can be moved over it (with the mouse) and change the size of the element (whether it be the size of a photo or font).
3. The position of the elements is passed in the post request.
Example: https://smmrecover.com/members/editor

I don't know which way to dig and google - please help.
UPD:
Google didn't help. Similar questions from the Toaster began to help.
Drag and drop: https://learn.javascript.ru/drag-and-drop

Answer 1

fabricjs.com