I asked myself the same question, because they want the physical proof of purchase. And that's what I found out.
Basically, your legal 2-year warranty claim in Switzerland against the seller applies.
https://www.srf.ch/sendungen....
The manufacturer may or may not grant you a longer warranty. On ecoflow.com it says in the FAQs.
https://www.ecoflow.com/de..."The warranty is valid for 500 operating hours or 2 years, whichever comes first."
And here it says something about 5 years for the River 2.
https://ch.ecoflow.com/pages...That's why I registered, but I've never had any problems with my devices. So I don't know how it works in practice and what is granted.