Might be worth asking in the derestricting section of the forum. You'll need to specify which motor also. It is illegal to do but many have done so.
Good luck!
The guy also has no profile pic or photos which is a bit alarming. Anyone can register the bike to them etc best thing to do is nip to a specialized dealer and get them to check the number against the database
He can screen shot it from the app, I did this when selling my levo sl as the frame sticker had rubbed off. Maybe a local shop who is a specialized dealer could check it for you or inform you the right way to proceed.
The suspension on that bike alone is worth nearly £1700. Its probably stolen.
Get him to send you the details via the app, anyone can connect to a levo via the app so he has no excuse. This will show you the frame number and details.
If it is stolen any motor work you get will flag up its...