Thanks for the response. I have been able to get through the problem, however at the time I tried the bluetooth button function but it wouldnt work. When I pressed it, Cortana responded by saying I need to setup the device using the Cortana app which wasn't available to me on PC, iPhone or Android. The solution I found is by using an older android phone, Note 5, and downloading an older version of cortana app from third party website which had the option to add device. After setting it up and connecting to wifi, a week after the cortana got automatically decommissioned from the device and now I can use it as a bluetooth device only. I downloaded cortana app version 3.2.
Hope this thread might help others in the same situation.