How to enable Slider Rev in the header & work with the side menu?

t1dhvls

In regards to the BeTheme template below:

https://muffingroup.com/betheme/website/hairdresser3/

I want to edit the header of this template and not sure how to. There is NO header template made under BeTheme so:

1.  Where do I control the content of the header? I can edit the menu links. If there's no side bar template, what is telling the page to use the menu with a SR overlay?
2. How do I change the background color behind the SR template? I think it part of the menu??
3. I'm using Elementor Pro, but BeTheme must be controlling the header as the is no reference in Elementor.

FYI - If using this template, the sections need to be converted to containers.

Thanks in advance.