Inova Microlight Open Can Anyone Help Me Fix My Broken Inova Microlight?

Can anyone help me fix my Broken Inova Microlight? - inova microlight open

I have bought recently, a key fob Inova Microlight, worked perfectly stopped working until recently. The batteries are new and the lamp is either [tested elsewhere Inova] Is the on / off-chip in it? Can someone tell me how I can solve this problem? Thank you.