Are you a delegate?

[aki]

If you're a delegate who has just signed up for discourse, please join the delegates group by clicking "request" on the group page.

[yulia]

is there a way to send messages on this?

[aki]

Yup. Clicking or tapping on someone's avatar will give you this "message" button:

. There's also one on the top right corner of each user's profile page, as well as some group pages (such as the TC39 Chairs group)