ReferenceError: json is not defined
at /app/node_modules/passport-slack/lib/passport-slack/strategy.js:92:16
at passBackControl (/app/node_modules/oauth/lib/oauth2.js:134:9)
at IncomingMessage.<anonymous> (/app/node_modules/oauth/lib/oauth2.js:157:7)
at IncomingMessage.emit (events.js:326:22)
at endReadableNT (_stream_readable.js:1226:12)
at processTicksAndRejections (internal/process/task_queues.js:80:21)