NathanU User

Script throws error because jquery library is not referenced. Fixed by adding @require to jquery CDN:

// ==UserScript==
// @name        Auto-Claim Itch.io Bundles
// @author      jnaskali
// @copyright   2020, Juhani Naskali (www.naskali.fi)
// @license     MIT
// @version     1.0
// @namespace   https://www.naskali.fi
// @downloadURL https://openuserjs.org/install/jnaskali/Auto-Claim_Itch.io_Bundles
//
// @match       https://itch.io/bundle/download/*
// @grant       none
//
// @require     https://code.jquery.com/jquery-3.5.1.min.js
//
// @description Automatically clicks all claim links on itch.io bundle download pages. Especially useful to (semi)automatically claim the over 1,500 games in Itch.io Bundle for Racial Justice and Equality. Just add the userscript and visit all download pages to claim the items to your library.
// ==/UserScript==

$(document).ready(function() {
  var clicked = 0;
  $('button[value="claim"').each(function() {
    $(this).parent().attr('target','_blank'); // change claim links to open in new tab(s)
    $(this).click();
    clicked++;
  });
  console.log("Auto-claimed " + clicked + " buttons.");
});

(Also added $(document).ready(function() {...});)