Spring points connection - bolt simulation

Hi all,
I would like to simulate the presence of a bolt (and his pre-load effect) on two plate.
I setup the static simulation, adding two reference point (rigid connected with the nearest surfaces). I try to add a spring that can connect the two reference points but I’m not able to find the right tool on the menus.

Did I make something wrong or there is another workflow to add this feature?

Thank you in advance.

Marco F.

Two-node springs are not currently supported and require manual keyword edits: Spring between two nodes