index.tsx (Provider setting)
변수 설정 및 선언해둔 함수를 호출(fetchCoin : 함수명 ) : userQuery hook
const { isLoading, data } = useQuery<ICoin[]>('allCoins', fetchCoins);
const { isLoading: tickersLoading, data: tickersData } =
useQuery<PriceData>(['tickers', coinId], () =>
fetchCoinTickers(coinId)
);
<>
<GlobalStyle />
<Router />
<ReactQueryDevtools initialIsOpen={false} />
</>
<QueryClientProvider client={queryClient}>
{/* The rest of your application */}
<ReactQueryDevtools initialIsOpen={false} />
</QueryClientProvider>