AIMesh node (RT-3100) username & password

Hi All,

Need to upgrade my AImesh node (ASUS RT-3100) firmware. On the main Router (ASUS RT-AX88U), I go to Administration -> Firmware Upgrade and click on Upload for the AIMesh Node. I am presented with a login screen to the AIMesh Node. I don't recall ever seeing that before. Anyways, I tried using my admin username & password on my main Router. That didn't work. I tried the default username & password. That didn't work.

Anyone else encounter this?

Please advise.

Thanks,
Randy