1.) Make sure you also install NBTAPI as its a dependency
2.) Once you do that you'll see:
If you look at the logs an error is being thrown
22.04 01:43:21 [Server] ERROR Could not pass event PlayerInteractEvent to gravy v1.4.7
22.04 01:43:21 [Server] INFO java.lang.NullPointerException: ItemStack can't be null/Air!
22.04 01:43:21 [Server] INFO at de.tr7zw.nbtapi.NBTItem.<init>(NBTItem.java:27) ~[?:?]
22.04 01:43:21 [Server] INFO at com.nefilto.gravy.utils.TokenUtil.isToken(TokenUtil.java:56) ~[?:?]
22.04 01:43:21 [Server] INFO at com.nefilto.gravy.listeners.TokenListener.interactEvent(TokenListener.java:116) ~[?:?]
22.04 01:43:21 [Server] INFO at com.nefilto.gravy.listeners.TokenListener.onStarUse(TokenListener.java:106) ~[?:?]
22.04 01:43:21 [Server] INFO at com.destroystokyo.paper.event.executor.asm.generated.GeneratedEventExecutor531.execute(Unknown Source) ~[?:?]
So, still doesn't work. My guess is a version mismatch between Gravy and NBTAPI