Within Teamwork, you can easily start a conversation with someone on your Teamwork Chat site.
On your Teamwork site, go to the People subsection of the main People area.
In the list of people on your site, when you hover over a particular person, you will see the pencil icon to the far right of their details, to edit their profile.
At the top of their profile, to the right of their name, you will see an option to Start Chat.
Once you click the Start Chat button, it will automatically launch the web version of Teamwork Chat in a new tab, opening a conversation thread with the selected user.
If Embedded Chat is enabled, selecting Start Chat will open within an embedded chat window.
For more information, see: Creating a Conversation or Channel