Do i need a numberplate light by law on my moped?

Hi, ive got a cpi gtr 50 moped and the owwner befor me came off and the numberplate light and bracket broke, but the n7mbrrplate will still go on, but do i aftually need a numberplate light by law? Can i have a small refleftor on the botton corner of the plate instead? Also if i do need one, does anyonebknow where i can get one. thanks.