Careful with following instructions on talk or together! There are several serious misunderstandings on how SFOS works.

For starters, "installed apps" may cause dependency issues that get resolved by doing a "version --dup" even before you attempt to do anything else. Setting the release version with ssu and using version leaves out sanity checks the gui-updater does. Rebooting the system is properly done with dsmetool on cli or gui only, all other variants you may know from desktop computers may work in most circumstances and brick your devices in others (like never use "reboot" on SFOS cli especially not after an upgrade). If there was something wrong with the upgrade and you fail to recognize it you may brick your device and keep both pieces. There should be a comprehensive list of stop-releases on together.

I could go on fo hours writing up what you can and should not do, what is save to assume and append a beginners guide - oh wait, did most of that on tjc (together by jolla https://together.jolla.com/).