Even if you don't have a fb account you should still be able to see it

https://en-gb.facebook.com/marketplace/item/229503902491244/

The reg is for a Honda X8R which looks nothing like that (and nor does any other Honda)?

This looks very similar.

https://www.bikeexif.com/bmx-with-motorcycle-engine

No, it's not a X8R or XBR or anything really. Neither is it a Honda Cub, from which it clearly derives the front forks.
Whatever it is, I do like the engineering and build quality (enough to actually consider it as a toy).

Here is my Locost version.....

Youtube Linker.....

Fully road legal in South Africa, but not in UK.

No idea of legality, but it does look like a very cool toy!