why are my LED lights not turning on?

Sounds like the driver has failed. If a quality product, there might be a warranty. If a cheap junky product, you probably can't even find the company, at least operating under the name you bought them from. That's part of the business plan that makes such things cheap, in every sense of that word.

In either case, you'll need new lights or at least new compatible drivers for the lights if you need working lights.