Not completely sure i understand your question but hopefully this will help.
Step 3: west flash This builds your application then flash your device.
So steps to flash your application are: Step 1: Identify port
Find port on Linux
Open terminal and type: ls /dev/tty*.
Note the port number listed for /dev/ttyUSB* or /dev/ttyACM*. The port number is represented with * here.
Use the listed port as the serial port. For example: /dev/ttyUSB0.
Step 2: Update the standard config file This is defined at 'scripts/west_commands/runners/bossac.py' as DEFAULT_BOSSAC_PORT = '/dev/ttyACM0'. Update the port identified in Step 1
Step 3: Build and Flash Board Run West Flash
If configured correctly West will build and write application to board.
