Hi @ Vicente Morales,
According to the User guide for your mouse, the LED light is a power On/battery level indicator.
This appears to be its’ only function.
You state that the mouse performs OK so the only problem for you may be when the battery level starts to fall to a low value, the mouse starts to behave erratically and you have forgotten that the LED doesn’t work/flash to remind you about the low battery state and you're wondering what’s going on.
There is a [https://www.logitech.com/en-us/footer/terms-of-use?id=3101|3 year manufacturer’s warranty] (depending on location) on your device (as shown on this [https://support.logitech.com/en_us/product/wireless-mouse-m215/warranty|webpage], so perhaps you may wish to check this out for your mouse to see if the warranty is still valid. Just a thought.