<button href='javascript: void(0)' onclick='fetch("https://raw.githubusercontent.com/username-pass/bookmarklets/dev/all-bookmarklets.js").then(function(response) {response.text().then(function(text) {let win = document.getElementById("webCont"); win.innerHTML ="test"; alert(document.getElementById("webCont").innerHTML); win.innerHTML = "hello"; win.eval(text);});});'>test4</button>