Your Netgear Orbi Satellite RBS20 should be simple enough to set up! First, power up the satellite and place it near to the router. Next, wait for the white LED pulse. The Sync button on both satellite and router must be pressed to pair the satellite with the router. The LED will glow a steady blue once the connection has been established.

The satellite can solve problems and issues at a reset; the Orbi Not Detecting Satellite is one of them. Locate the reset button on the rear, press and hold for ten seconds, and release when the indicator LED starts blinking amber. Proceed with the setup again after the reset. 

For your reference, set the satellite within range, and do ensure firmware upgrades are applied. Go for seamless coverage with the Orbi system once working!