$P_c(4457)$ interpreted as a $J^P=1\mathrm{/}{2}^{+}$ state by ${\bar{D}}^0{\mathrm{\Lambda }}_c^{+}(2595)$-${\pi }^0{P}_c(4312)$ interaction

$P_c(4457)$ has been discovered over five years, but the parity of this particle remains undetermined. In this letter we propose a new interpretation for $P_c(4457)$, which is the state generated from the coupled-channel ${\bar{D}}^0{\mathrm{\Lambda }}_c^{+}(2595)$ and ${\pi }^0{P}_c(4312)$ since they can exchange an almost on-shell ${\mathrm{\Sigma }}_c^{+}$. In this scenario, the parity of $P_c(4457)$ will be positive, which is different from the candidate of the bound state of ${\bar{D}}^{\ast }{\mathrm{\Sigma }}_c$. The main decay channel of $P_c(4457)$ in this model is $P_c(4312)\pi$. We propose three processes ${\mathrm{\Lambda }}_b^0\to J\mathrm{/}\psi K_{s}p{\pi }^{-}$, ${\mathrm{\Lambda }}_b^0\to J\mathrm{/}\psi K^{-}p{\pi }^0$, and ${\mathrm{\Lambda }}_b^0\to J\mathrm{/}\psi p{\pi }^{-}{\pi }^{+}{K}^{-}$ to verify $P_c(4457)\to P_c(4312)\pi$.