Go to "Settings" -> "General" -> "bluetooth". Turn on the keyboard by pressing the power button on the right. The light on the keyboard should blink after 5 seconds, which means that the device is ready for connection.
On the iPad bluetooth toggle lever to the on position. Starts the search for devices. Once the iPad sees the keyboard, click on the name of the keyboard. In this case, Apple Wireless Keyboard, as you can see from the screenshot.
It will show the code window. Code — four digits that must be entered on the keyboard and press the Enter button. The keyboard is ready to use.
To disconnect the appliance temporarily turn off your Bluetooth settings on your iPad or disconnect the keyboard. After a reverse turn in the future, the keyboard will connect automatically without re-entering the code.