Alternative sign-in method

I have moved to open-source and am trying to use join on a phone without Google Play Services (microg). When trying to sign-in using the Join app, I get the error message, "Couldn't authorize on server: java.lang.illegalstateexception: GoogleApiClient is not connected yet." 

Is there another way to authorize Join via Google or to use another sign-in method not dependent on Google's API?