Token Name Number (Am I Missing Something?)

So I'm super keen to use the Token Name Number script to automatically number multiple monsters of the same race etc. I created my character, in this case a Merrow, dragged him onto the map. Selected the token, changed the name to Merrow %%NUMBERED%%, got back into the character, and chose the selected token as the default token. Then attempted to both copy and paste the token, and/or drag the character to the map again, which, of my understanding should have copied over tokens titled, Merrow 1, Merrow 2 etc etc. It just keeps copying/dragging tokens named Merrow %%NUMBERED%%. What am I doing wrong? This is my first time using script in Roll20, and am trying to improve my games and love the idea of Token Name Number. Is there a setting I need to select/change? Help (thanks)!

You have to have the api script installed on the api settings page for your game, which is a pro subscriber perk.  According to the label by your name,it looks like you are a plus subscriber.  Is this in a game you created, or one created by a pro subscriber who promoted you to GM?

Okay, that I didn't know. I'll upgrade and see what happens.