The Arctis 7 can be setup on the Nintendo Switch and Mobile using the provided 3.5mm cable. To use your Arctis 7 via the 3.5mm cable, please plug in the cord into the 3.5mm port on your Switch (tablet mode) or mobile device.
The Arctis 7 can be used wirelessly on the Nintendo Switch while in docked mode. Simply plug in the wireless USB transmitter into the USB port on the dock and turn on your Arctis 7. If it does not pair to the transmitter automatically it will need to be paired manually. Please see: How do I pair my Arctis 7 to the wireless transmitter?