WSJT-X activity window

The WSJT-X activity window is opened from the "View" menu.
It displays the same information as the main window, but for the call from WSJT-X's "DX Call" field.
A clickable link to QRZ or HamQTH is available if the call is found in the call book.
There are also up to six buttons, if macros are configured in the preferences, for setting the free text message in WSJT-X

WSJT-X activity window

Clicking one of the buttons is equivalent to typing a new message (old contents are discarded) in to the WSJT-X free text message field or "Tx5" field (both are updated) and then clicking the "Now" radio button for the "Tx5" field if tab one is current or clicking the "Free msg" radio button if tab two is current. This requires that WSJT-X is set to Accept UDP requests:

WSJT-X preferences