Dark armpits... how do I fix it?

My mom has made me self conscious my whole life about how dark my armpits are compared to the rest of my skin. She tells me they look dirty and gross (I mean they are armpits but she is rude). Ive exfoliated, tried different razors, tried different deodorants because I read aluminum in it causes this??, and applying freakin lemons to my armpits to lighten them (internet at home search 🙄). Nothing has worked. My right one is the worst one. Does anyone have any advice on how to fix my dark armpits 😖