const output = document.getElementById('output'); let page_url = "http://127.0.0.1:4433/s3/style.css"; document.getElementById("newtab").addEventListener('click', async function(e) { browser.tabs.create({ url: "/main/main.html" }).then((t) => { if (t.id) { output.innerText += t.id } }) }) document.getElementById("replacer").addEventListener('click', async function(e) { browser.tabs.executeScript({ code: injection }) browser.tabs.executeScript({ file: "inject.js" }); }) const injection = ` let head = document.getElementById('anchor'); head.innerText = "${page_url}"; `