How do I use the shrine? I click on check, but I can't interact with it.
Talk to Kimiko about it and listen carefully to her hints. Some things may need to be bought from the horned vendor.
It's telling how to get more talismans (which I've already done), but not how to use them in the first place
There you need to add a body, and then add the required number of talismans to it. Try it, the interface is quite simple.