It is not reasonable to expect a meaningful suggestion when we really have no idea of your concern.
A picture is worth a thousand words. Please consider posting a photograph of your concern. It is possible that you have hemosiderin staining from a bruise. This is very uncommon. Another issue that is seen after filler is simply a change in how the thin skin is presented with filler and the fix is removal of fill or in some cases, the use of cover up makeup because overall the eyelids look better with the filler.
Lasers peels and creams
Seek out a dermatologist to help you.Lasers, peels, microneedling, and medical grade skin care such as RetinA can help with these dark areas.