[SOLVED] Empty response for slash command

Hi everyone,

Please need your help. I am pretty new in Mattermost and node-red and I am trying to create a slash command for mattermost using Nodered in Bluemix. I already make the slash command work with Slack, but when I tried the same with mattermost, I have the following response: "Command with a trigger of 'wmax' returned an empty response". Checking the debugs nodes in Node-red show me the same for both cases (Slack and Mattermost).

Thanks in advance,

Regards
Luis