How to install the firmware name containing the name RT-AC42U to RT-ACRH17?

How to install the firmware name containing the name RT-AC42U to RT-ACRH17?I installed the software in both ltb and bin formats respectively in opboot mode and it just doesn't respond and I can only download the firmware with the name RT-AC42U under the website

Seen Need help installing OpenWrt on asus RT-ACRH17 REV 1.60 aka RT-AC42U ?