You can check out the GitHub repo linked above, and follow the usual OpenWRT build instructions, if that's an issue let me know.
Otherwise you can download from https://1drv.ms/f/s!AsfW32P1XQXagaRzSVeC_ovaFXKqvw?e=DiwIBP
Freshly built with a new checkout (on a different machine from my dev machine)