Chat Ops integration with OO and slack - Failed authentication

Hi everyone!

We're trying to deploy the integration between OO and Chat Ops using slack, but when trying to login in the hubot server it fails while using a valid username of OO. 

While checking the logs we see the following error:

ERROR Request error: { [Error: tunneling socket could not be established, statusCode=503
at ClientRequest.onConnect (/opt/microfocus/itom-maestro-oo-bot/scripts/hubot-oo/node_modules/tunnel-agent/index.js:166:19)
at Object.onceWrapper (events.js:277:13)
at ClientRequest.emit (events.js:189:13)
at Socket.socketOnData (_http_client.js:475:11)
at Socket.emit (events.js:189:13)
at addChunk (_stream_readable.js:284:12)
at readableAddChunk (_stream_readable.js:265:11)
at Socket.Readable.push (_stream_readable.js:220:10)
at TCP.onStreamRead [as onread] (internal/stream_base_commons.js:94:17)
] code: 'ECONNRESET' }
2019-11-01T00:04:51.335Z - info: Function authMethod getting error message: Error: System error

Did anybody else faced this problem?