how to compile wureguard for AC815S-1A1NAS

Hello!
I have AC815S-1A1NAS LTE wifi router and wanted to add wireguard support to it. I see
https://kb.netgear.com/2649/NETGEAR-Open-Source-Code-for-Programmers-GPL and source code which I can use to build but I didn't find any HOW-TO guide to add wireguard module. I've tried to use wireguard.ko that was compiled ed for AC810 - but it can't be recognized by router. Any suggestions?