If you want to control your Nuki device remotely, you need the Nuki Bridge
The Nuki Bridge brings your device online and makes it remotely available for all authorized users.
Note: The Smart Lock 3.0 Pro has a built-in Wi-Fi module. So you can manage it remotely at any time. You do not need a Nuki Bridge.
One Nuki Bridge can be paired with several devices. It is important that every Nuki device is within Bluetooth range of the Bridge and that there is a good connection between the devices.
A) Pairing via Nuki app
Open the menu in the Nuki app (top left) and choose "Add devices" > "Bridge" to search for your Bridge in maintenance mode. Then you can pair the desired Nuki device with the Bridge comfortably via the Nuki App.
B) Pairing without Nuki app
You can also connect a Nuki device and the Nuki Bridge without using the Nuki app (after successfull initial Bridge setup). To pair the Bridge with your device, press and hold the button on both your Nuki device (e.g. Smart Lock) and your Bridge for 5 seconds to connect them with each other. The devices are in pairing mode when the lights are permanently glowing. The pairing is complete when the Nuki device and the Bridge stop glowing and the Bridge LED is flashing for 3 seconds afterwards.