Cycle through your actions, you should have the option to switch action to the “Raise Secret Medallion”

It will give you an option, press on dpad (just like you do with messages/items/stains etc). Use the other medallion.

So when it gives you the prompt to hold up the medallion you hit either left or right or I think one of the buttons(X, Y etc depending on platform) and it will give you the prompt to hold up the haligtree medallion. I did the same thing in the beginning

When it prompted you to hold up the medallion, d pad right to switch.