You can use the flash loader demonstrator.
http://www.rakwireless.com/en/download/RAK811%20TrackerBoard/Tool
In this document the procedure is explained on page 10. http://docs.rakwireless.com/en/RAK811%20TrackerBoard/Software%20Development/RAK811%20TrackerBoard%20User%20manual%20V1.1.pdf
In CoIDE go to the Configuration window and there to Output.
Make sure that Create BIN File is checked.
When using the flash loader demonstrator make sure you change the file type to .bin in the file selection dialog box when you locate the .bin file from your compile run.
