Scroll up button not visible (2)

Perhaps because my reply some 3 days ago was not seen, I thought it better to open a new thread ….

First I wrote:
Having this page loaded in Elementor, at scrolling, the Scroll Up arrow in the right corner below is visible and works as it should.
But when the page is loaded as a page outside Elementor, so as if it will be presented in public, that button is not there.
Can you help me out with that?
(I have the same at some more pages).

That was replied with:
The scroll button is not a feature of Elementor but of your theme, so you need to take this up with your theme provider.

And my answer:
Hmmm.. I may have expressed myself unclear:
Nicolas (the maker of my OceanWP theme) wrote me:
“You need to ask to the Elementor support team, why on this page: https://boudicca.de/wp/why-boudicca/ you have this error in your console: Uncaught ReferenceError: elementor is not defined.
This error comes from the frontend.min.js file, it is not an issue with the scroll up button, this button will work when this JS error will be fixed.”

Hope you can help me out with this.

The page I need help with: [log in to see the link]