For this you should use the other playlist tabs, or load it to the main playlist tab. Also, scheduled events with the "Overlay playback" flag can also sent their titles, but it needs to be enabled in the settings:
https://manual.djsoft.net/radioboss/en/schedule_settings.htm
I don't think sending the titles from cart wall make much sense, carts are designed to be quick effects playing on top of the main content, changing the title from there seems unexpected. Same, for a lesser extent, is true for AUX players.