In 2011, Sun (Sci. China Math. 54 (2011) 2509--2535) made the following conjecture: for any odd prime $p$ and odd integer $m$,
$$\frac{1}{m^2\left({m-1}\atop{(m-1)/2}\right)}\left(\sum^{(mp-1)/2}_{k=0}\frac{{\left(2k\atop k\right) k}}{8^k}-\left(\frac{2}{p}\right)\sum^{(m-1)/2}_{k=0}\frac{\left({2k}\atop{k}\right)}{8^k}\right)\equiv 0 ({\rm mod}\, p^2).$$
By applying the creative microscoping method introduced by Guo and Zudilin (Adv. Math. 346 (2019) 329--35), we confirm the above conjecture of Sun.
