eMMC question for Rock Pi 4B+

Is the eMMC drive removable and thereby upgradable, or is it permanently affixed to the 4B+?

well…by the pictures it seems permanently affixed, my rock pi x is affixed in the same way as the rock pi 4b plus

eMMC is none removable on 4B+. Install from USB OTG to eMMC is possible.

or after booting from sdcard

How to enter Maskrom mode on board Rock Pi 4B+?

Boot the board to maskrom mode:
3. Power on the board
5. Now plug the eMMC module and proceed the next step to flash.
https://wiki.radxa.com/Rockpi4/dev/usb-install

Instruction from Rock PI 4B does not fit.
Under the HDMI connector 4B+ there are buttons most likely for the firmware, but there is no information on the site.

Since eMMC is not removable, what is the procedure to install an OS image via USB OTG?

Hey guys, new here coming from pine64 community. I would love to know this as well! I can’t find any info on this. I’m trying to push Armbian (CLI) image but have no idea how to do so.
Any help would be appreciated!