Trac integration

Hello everyone.

I am testing Mattermost (3.4) and there are some things that I cannot find. I am trying to integrate Trac with Mattermost and the documentation says that I should go to "System Console --> Integrations --> Webhooks and Commands". But Under Integrations I only have "Custom Integrations" and "External Services". Does anyone have any idea why I do not see the "Webhooks and Commands" link?

thanks