<input aria-label="text field" value="Click inside this input field" />

document.querySelector("input").addEventListener("click", (event) => {
  const x = event.clientX;
  const y = event.clientY;

  const caret = document.caretPositionFromPoint?.(x, y);
  if (!caret) {
    log("Not supported");
    return;
  }

  const node = caret.offsetNode;
  const offset = caret.offset;

  log(`offsetNode: ${node}`);
  log(`offset: ${offset}`);
});