Well they do even sell rings for Eleviia. But yes, you have to have some kind of rope that would work with it. I am just saying, that Eleviia is (if your door dimensions are right) by far the most easy and the most secure of all those non permanent doorway options. Something like this https://www.amazon.com/DreamGYM-Doorway-Chin-up-Pull-up-Support/dp/B07CVFT1DB

is maybe an alternative.