Ah ok. I didn't find it. The good thing is that it's easier to export with the python script.
Stefano mentions it here: https://moi3d.com/forum/index.php?webtag=MOI&msg=6186.74

You can export the rsdoc directly to sat with that script that uses the sabsatconverter where DesignSpark is installed.

So you can open cmd and just write: rsdoc-to-sat.py myfile.rsdoc
You have to have Python3 installed.