Install V2Ray Client on OpenWRT and Configure Vmess
Commands: https://gist.github.com/amanjuman/cd1...
Make sure your router has at least 16MB of flash storage otherwise you can install V2Ray. In such a case if your router supports USB or external storage you can follow the ext root method.
You can either do this whole process from OpenWRT Luci Interface or SSH. However, I recommend doing this using SSH.