Q: The keyboard does not work, unable to pair in this process , I read the previous comments on this topic, are you actually testing this ??

You are not communicating with Apple on these forums, we are all end users like yourself. Try doing a SMC reset 2-3 times and see if this helps your connection issues. Otherwise please use a USB keyboard and attempt to re-pair the wireless keyboard.

iMac SMC and PRAM reset

This worked for me:

1. Switch off the keyboard by holding down the power button for at least 3 seconds
2. Click the Bluetooth icon in the menu bar
3. Click on “Set Up Bluetooth Device” or “Open Bluetooth Preferences”
4. Turn on the keyboard by holding down the power button, BUT DO NOT LET GO OF THE POWER BUTTON. It must be kept held down through the entire process.
5. The Setup Assistant will find the keyboard, so click the name of the keyboard, and then click on “Continue”. Make sure you are still holding the power button down.
6. You will be prompted for the Pairing Code. You can now release the power button, type the pairing code on the keyboard and then press return. There will be a slight delay whilst the pairing completes (a few seconds)
7. The keyboard will now be Paired.