Hi,
here is a webpage that gives Overview of RAppID Bootloader. You can launch a live presentation video or just open a presentation document.
Overview of RAppID Bootloader|NXP
Btw, please ensure the USB-to-SCI (UART port) operates correctly.
Check on your PC in Device and Printers if you see as below:

and Device Manager:

Hope this helps.
Regards,
iggi