@hoseaemmanuel iFixit is more focused on the hardware aspects of devices. I would suggest you check YT videos as well as check forums that deal with Software, Firmware, flashing ROM's etc. [https://xdaforums.com/t/note-20-software-update-issue.4677998/|like this] or even the [https://eu.community.samsung.com/t5/other-galaxy-s-series/your-current-software-version-isn-t-supported/td-p/6413531|Samsung Site] itself