Ctrl+click to copy from lastpass fields

lastpass.js

// ==UserScript==
// @name Lastpass copier
// @namespace ar1as.space/lastpass
// @match https://lastpass.com/*
// ==/UserScript==
'use strict';

const copyToClipboard = target => {
  const { type, selectionStart, selectionEnd } = target;
  target.type = 'text';
  target.focus();
  target.select();
  document.execCommand('copy');
  target.type = type;
  target.setSelectionRange(selectionStart, selectionEnd);
};
(() => {
  const observer = new MutationObserver((records, observer) => {
    for (const { addedNodes } of records) {
      for (const node of addedNodes) {
        if (node.id == 'siteDialog') {
          node.addEventListener('click', ({ target, button, ctrlKey }) => {
            if (button == 0 && ctrlKey)
              if (
                target.id === 'siteDialogPassword' ||
                target.id === 'siteDialogUsername'
              ) {
                copyToClipboard(target);
              }
          });
          observer.disconnect();
        }
      }
    }
  });

  observer.observe(document.body, { childList: true });
})();