Best Setup for a backstay tension adjuster

Never having seen my J24 ‘project’ boat with the mast up, I am a bit confused trying to rig the backstay tension adjuster.
I have the lines leading back to either side of the cockpit just forward of the traveler. But I am sure that I need to insert a Vang-type pulley system to gain some mechanical advantage in tightening the backstay.
Can anyone share a photo (or refer me) of a good way to rig this on my boat? I have an empty eye strap on the starboard rear corner of the cockpit seat...

Best Setup for a backstay tension adjuster