The target high-level PES is finally fitted to 140 192 points with high-level energies, 7586 points were calculated at the level of UCCSD(T)-F12a/AVTZ, and the remaining points, namely, 140192-7586=132606, were predicted as a sum of the DFT energy and its correction. The same NN architecture for PESL is used for fitting PESH and the final fitting error is 0.467 kcal/mol. Note in this work, we focus on the kinetics of the title reaction below 1000 K, and thus the PESH may be not reliable for dynamics and kinetics simulations above 1000 K.