Try the explantion above (last post = solution) + read a little the barba.js docs (by deafult the transition is “fade” → to change this you must have some knowledge in code - or find freelancer)
- Remember you see the effect only in live-mode = publish site (like any other custom code and/or html block)
The idea is very simple: add code (before body) copy-paste - add simple structure (wrapper with same name - to all pages!!) - thats it. First try - than ask more Q