As soon as the operator answers the call, both user and operator are able to send messages each other, share links, contacts and other necessary data.
To start chatting with operator, the user should click the icon at the upper right corner of the Call window:
To start chat with the user, the operator should click the icon at the upper left corner of the dialog box:
To close the chat with user, the operator just clicks the chat icon again.
To close the chat with operator, the user should click the cross:
The user can get back to the chat after the chat is closed by clicking the chat icon and and read its history.
The user will not be able to read the conversation after the call window is closed.
The operator will be able to read the whole chat history with the current user, if this user calls him again.