To setup your Orbi router read this carefully:
Connect the orbi router using ethernet cable and connect your Orbi router to a power cycle. Wait for the Orbi router's ring LED to light solid white and then pulse white. Find the best location for your orbi satellite where it gets more than 70% of network strength. Make sure you are connected with the power source. Wait for the Orbi satellite's ring LED to light solid white, then + white, and then + magenta. The Orbi satellite's ring LED light pulse magenta for up to one minute while the satellite attempts to sync with the Orbi router. After the Orbi satellite's ring LED pulses magenta, it lights one of the following colors for 10 seconds then turns off: Connect your computer or mobile device to the Orbi router or satellite with an Ethernet cable or WiFi connection.
To connect with WiFi, Enter WiFi network default name (SSID) and default password, name password on the label on the Orbi router or satellite. Connect to that network from your WiFi-enabled computer system or mobile device. Download the Orbi app or visit orbilogin.com to set up your Orbi WiFi network. The Orbi router purple LED turns off after the setup is complete.
Source: How to setup Orbi router rbr50