alt-click-copy.user.js

// ==UserScript==
// @name                Alt Click Copy
// @namespace           http://tampermonkey.net/
// @version             0.1.0
// @description         Alt click an HTML element on the page to copy it to your clipboard.
// @author              mchpatr
// @match               *://*/*
// @icon                https://github.com/prmichaelsen/alt-click-copy/releases/download/alt-click-copy/save.icon.png
// @run-at              document-start
// ==/UserScript==
// Check the following resource to determine if you need to enable browser permissions for clipboard writing https://caniuse.com/mdn-api_clipboard_writetext
(() => {
  document.addEventListener("click", function(event){
    const clickedEl = event.target
    if (event.altKey && clickedEl && clickedEl.textContent) {
      event.preventDefault();
      event.stopPropagation();
      navigator.clipboard.writeText(clickedEl.textContent);
      return false;
    }
  });
})()