I'm trying to append a footer after a navbar but the nabber does not have an ID and I can't give it an ID. The navbar is the only element in the whole page to have the class "super-navbar" so I'm trying to append it thanks to document.getElementsByClassName('super-navbar')

But it does not work, here is the full code:

headerElement.innerHTML = 'the code I'm trying to append'

const target = document.getElementsByClassName('super-navbar')
const thisElement = target[0]
document.thisElement.appendChild(headerElement);```