DataTransfer: метод setData()

setData(format, data)

<div>
  <p id="source" draggable="true">
    Select this element, drag it to the drop zone and then release the selection
    to move the element.
  </p>
</div>
<div id="target">Drop Zone</div>

<button id="reset">Reset example</button>

div {
  margin: 0.5em 0;
  padding: 2em;
}

#target,
#source {
  border: 1px solid black;
  padding: 0.5rem;
}

.dragging {
  background-color: pink;
}

const source = document.querySelector("#source");
source.addEventListener("dragstart", (ev) => {
  console.log("dragStart");
  // Change the source element's background color
  // to show that drag has started
  ev.currentTarget.classList.add("dragging");
  // Clear the drag data cache (for all formats/types)
  ev.dataTransfer.clearData();
  // Set the drag's format and data.
  // Use the event target's id for the data
  ev.dataTransfer.setData("text/plain", ev.target.id);
});
source.addEventListener("dragend", (ev) =>
  ev.target.classList.remove("dragging"),
);

const target = document.querySelector("#target");
target.addEventListener("dragover", (ev) => {
  console.log("dragOver");
  ev.preventDefault();
});
target.addEventListener("drop", (ev) => {
  console.log("Drop");
  ev.preventDefault();
  // Get the data, which is the id of the source element
  const data = ev.dataTransfer.getData("text");
  const source = document.getElementById(data);
  ev.target.appendChild(source);
});

const reset = document.querySelector("#reset");
reset.addEventListener("click", () => document.location.reload());