Bookbrainz site | unable to get OAuth access token | mismatched URI


hello bookbrainz devs!

I have got the site up & running. I have even registered the application on musicbrainz to get client ID and client secret as indicated in github readme page. When I try to click sign in/register, bookbrainz is doing authorization request like stated on this page I am getting mismatched URI. the callback URL given by bookbrainz site is http://localhost:9099/cb


For posterity: after some investigation on the IRC chat, the issue was with the callback in the MB developer application ( the callback needs to be exactly the same as the one under musicbrainz.callbackURL in config.json (by default, http://localhost:9099/cb)