Found this 1998 Veuve Clicquot champagne bottle whilst helping my parents move. Any info on it?

So whilst I was helping my parents move out some stuff we found this bottle of Veuve Clicquot Ponsardin “La Grande Dame” Brut from 1998. My parents bought it for a special occasion at the time but then forgot about it in the corner of a cupboard in their room.

Thing is, we don’t know much about champagne, so we just want to know if: 1: is it “expired”? 2: can we sell it? 3: how do we go about the process of selling it? Like do we go to a wine shop and offer it?

Any info is appreciated. Thank you in advance!