I'm not able to show the texts in the chat, like the demonstration in YouTube

[jose-renato-m]

Hi, there.
I'm not abble to send a text. In console I may see that the text is going, but I'm no abble to see it in front-end, like John presents in his video at YouTube. I've tried to signin with a user, and signup as other user, and signin as this other user and nothing happens.
I appreciate if you could help me as soon as possible.
Regards.