Asus rt-ac57u - can't find factory install firmware?

Newbie here

I have recently bought the ASUS RT-AC57U and I want to install OpenWRT on it.

The link to the tech specs only shows a downloadable file for an "UPGRADE" but not a factory install.

Does anyone know how I can obtain the install file please?

Also, would I be able to connect to IKEv2 client and/or Wireguard client after I upgrade?


Have you studied the wiki page for RT-AC57U v1?

But isn't sysupgrade only to be installed when you already have OpenWrt installed on your router?

No. It depends on the device whether or not a dedicated first install factory to openwrt image is required.