You can directly plug your other router into one of the Starlink Gen 3 router's Ethernet ports. The Gen 3 router has two Ethernet ports, which allow you to connect other devices or routers without needing an adapter. However, if you want to bypass the Starlink router entirely, you might need to use an Ethernet adapter depending on your setup, but this is not necessary for simply connecting another router to the Starlink Gen 3 router.