There are loads of examples on this forum honest, below is a thread to start with - once you have the console app data showing your decoded data then you know you can move on to Node Red via MQTT,
Remember the key goal here is to take raw data values (from sensors? maybe temp -2.68c) perhaps signed, decimal, or even simple true/false conditions and convert to values that can be sent via the uplink. These need to be sent efficiently as hex bytes (smallest number possible), this is the encoding process done on the device - likewise the app in the console is where you can do your decoding back to real world values.