RSSI value from Mavlink RC_CHANNELS_RAW message not displayed

I made some one way tunnel protocol for my LRS solution and it works fine with DroidPlanner, and Tower, except RSSI value which is send as RC_CHANNELS_RAW mavlink message, but it’s not displayed at all ;(.
What is required to display RSSI value (which mavling messages except RC_CHANNELS_RAW).
Thank you n advance