How do I get the current index of item at which the flatlist has stopped scrolling at and has snapped to?

const Scrollref=useRef();

<FlatList
    data={Data}
    ref={Scrollref}
    renderItem={...}
    keyExtractor={...}
    getItemLayout={...}
    initialScrollIndex={initialScrollIndex}
    initialNumToRender={3}
    snapToOffsets={Data.map((x, i) => (i*ITEM_HEIGHT))}
/>

I used this solution and although it does give the key index from viewableItems, it returns so on everytime the view is changed which seems very inefficient

is there anyway to get the key after the scrolling has stopped? maybe using onMomentumScrollEnd?