It is safe to use expired betadine medicated vaginal douche kit? it was expired january 2020?

No . please dispose of it

Expiration dates on drugs and other medical products often can be safely ignored if the product has been stored normally (e.g. without extreme heat) and the packaging is intact. The date does not mean the product stops working or becomes unsafe, only that the manufacturer hasn't done studies to know how long it lasts. It's best to replace when outdated, but usually effective and no harm if used.