DIAGNOSIS You're locked out. A factory reset wipes all settings, including your custom password, and returns everything to the default credentials printed on the sticker on the unit.
FIX Find the reset pinhole on the back of the Orbi router (it's next to the Ethernet ports). You'll need a paperclip. 1) With the router powered ON, straighten the paperclip and press and hold the reset button. 2) You'll see the ring light turn amber. Keep holding. After about 10 seconds, the light will start blinking amber. Keep holding. 3) After about 30 seconds total, when the light starts to pulse white, you can let go. The router will reboot itself. This process can take up to 5 minutes. When it's done, it will be factory fresh.
IF THAT DIDN'T WORK If the light sequence didn't happen as described, unplug the router, press and hold the reset button with the paperclip, and then plug the power back in while still holding the button. Continue holding for 30 seconds after power is applied, then release. This is the "power-on reset" method and is more forceful.
HEADS UP This resets ONLY the router you pressed the button on. Your satellites will need to be re-synced. Also, after the reset, you'll need to set up your WiFi network name and password again from scratch, and all your connected devices will lose their connection.