I want to build an Google home service

I want to link Oath2.0 with my existing Google home service and register new devices to different users. I have my own code and need modification in the existing code. I successfully implemented the Google Codelab washer sample from its documentation but it is working on the fake token and fake authentication. I want to complete the whole process of linking oath 2.0 and register new devices to different users using firebase. I want the Oath2.0 to process like this in video and register different devices based on firebase data.