Where does “κάποτε” come from?

κάποτε (Greek) comes from Byzantine Greek κάποτε, from Ancient Greek ποτέ, from Proto-Indo-European kʷokʷe, from Proto-Indo-European kʷos, from Proto-Indo-European kʷ- — The primary interrogative root.

κάποτε (Greek): sometime; formerly, once; at some point an unstated or indefinite time