RAK7391 Flashing issue

I have RAK7391 and I’m trying to flash the eMMC. I follow this tutorial here: RAKPiOS Quick Start Guide | RAKwireless Documentation Center but I have the issue seeing the RAK as mass storage on my computer.
I have RPI CM4 on my RAK.
Any help would be appreciated.

Thank you

Hi
You can flash the eMMC the same way you would on a Raspberry Pi IO Board. There are basically 3 steps:

  1. boot into flash mode by pressing the flash button in the bord while powering the board (or adding a jumper on the connector labelled “eMMC Flash” on the board itself). Holding down the button while powering the device can be tricky. You might want to try a few times. The jumper solution is easier but you have to have access to the board.
  2. Set the CM4 in USB Mass Storage Device using the rpiboot utility. Note this will vary depending on your OS.
  3. Use Balena Etcher (or other tools) to flash the image.

I understand you are having issues on the first step above. Correct?