lol..
I had my ST2S replaced with a brand new ST3 on 6/2 because of warranty issues. Had the ST3 for all of 1.5 hours before I experienced an error (210005), but the bike worked fine. The next day, the bike shut down 1 mile into a 1.5 mile ride to the gym, and wouldn't turn back on unless plugged in but wouldn't take a charge, and shut back down immediately when unplugged. Fantastic ride prior to that, but now I have two bricked Stromers sitting in my garage, and pulling teeth to find some sort of resolution. Probably coincidental, but the battery also wouldn't eject while working.
With that being said, there should be a Stromer portal someone at REI has access to where they will register the serial number. I believe only the dealer can perform the registration.
Good luck getting timely support. There are literally only two people who work at Stromer USA. My honest opinion, the bike itself is fantastic when working and a true game changer, but I'm over the constant headaches and general anxiety of whether or not my bike is going to quit on me. Others on this forum may disagree, but I would return to REI before it's too late and look at other options. Stromer isn't in a position to service these bikes directly, nor are they in a position to offer their dealers quality support. While most ebikes are in the same position, they also don't cost $8k.