So, i just made a booking with my points. It was very easy, to the point where I have to wonder why they bother with this nonsense.
1. I logged into my account and opened the chat with SJ.
2. I gave the agent all the information about the trip and passenger names (me + one other person).
3. She asked for my security code (which is available in the SJ app) and issued the tickets.
What's the point then? Why can't I just book this myself in the app if everything I need is in the app anyway?