I can help you, I suggest working with Chinese manufacturer. Because they are now the market leader in electric scooter. But the manufacturer should work based on International standards.
I already work oversea outsourcing from China to US and European companies .
I have contacts there, they know the market, and know who is the best manufacturer to work with, because, online communication with Chinese is not enough, you need to know them or know someone who know them. Especially for complicated product with security requirements and many standards to be met.
If you want it from Europe, I think price will be very high, but cutting edge, very high quality, I can help you too, but only by providing potential manufacturers who can do it.