When using the Hero-user desktop version, you will see a series of thematic icons on the left of your screen. The fourth icon starting from the top will take you directly to the chat environment.
When using the hero-user mobile version, you will find a series of thematic icons on the bottom of your screen. The fourth 'messages' icon will take you directly to the chat environment.
As a Hero, you have the possibility to chat with your set of connected Heroes in the network. So the more you connect, the more you can chat.