Trying again. Attaching image this time of a screen grab from my genealogy software program.
I do not know how to cite Riksarkivet. I do not know who runs Riksarkivet, who compiles the databases, who to give the credit to, or anything. I am only guessing when I have filled out the template that is the image I have attached.
It would be so much easier if I could just see an example of a citation for Riksarkivet. You say you have one, but I do not see it in your most recent edition (2017).