dark itchy skin funky smell

My neck, my armpits and my groin area are getting so dark is very itchy and have a funny smell

Rub potato slice daily for few weeks on dark area, it acts as bleaching agent. Use good quality moisturizer as dry skin often itch.
Try this- Massage such area with coconut oil half an hour before bath. wash it with soap and water. Do this regularly for a month and see the difference.