javascript - How can I get sessionStorage information with Chrome Extension -

I have a field on a tab's session collection with some information, I want to copy my Google extension to the clipboard Or want to show on some HTML so that the user can copy.

I have created a simple extension like this on JS:

  function rendererts (status) {document.getElementById ('position'). TextContent = statusText; } Document.addEventListener ('DOMContentLoaded', function () {renderStatus ("banner" + sessionStorage.getItem ("userToken"))});  

But the return is always "barerer undefined", but if I work on the console i

Thank you!