This popped up in my feed, seemed alright for the money although manual disc brakes and not UK legal
www.gunai-ebikes.com
Someone did a review here

GUNAI GN29 29 Inch 750W Motor 48V 15AH Electric Bike for Adult Electric Mountain Bike 21 Speed
GUNAI GN29 Electric Mountain Bike 750W Motor, 48V 15AH Battery 50km/H Max Speed.Free Shipping.Have A look And Find A Long-Range Electric Bike For Adults.Go Outdoors Freely.

Someone did a review here