Many thanks for your reply.
I would try to contact the seller for serial no and in mean time please let me pass you a link https://www.olx.bg/i2/ad/prodavam-velosiped-sgavaem-strida-ID7aJOz.html#:f0cb8d4863 to auction where you can find more pictures of greater details.
I am very suspicious there are no sticker or branding anywhere. Tend to believe it’s a replica