Hello, Raul, and thank you for your help.
Currently I am working on porting an open source project (TockOS) for use with the LPCXpresso55S69 boards. I didn't have much difficulty with the documentation, until I managed to compile the software and found that I don't know how to flash the code (ELF format) to my board.
I have used mcuxpresso a little in the past, and I managed to write a blinky led and a hello world app for use with this board in the IDE. However I am not sure what commands the IDE uses in order to flash my code on the board.
It would be greatly appreciated if you could provide some more specific help on how to find the script the ide uses to flash code on the board. Until then I will start looking on the document you linked.