(Tutorial) How to make a Villager with GUI!

Hello! Here I am with one more Tutorial!
Today I will teach you how to make a villager who has an inventory (GUI) with functional changes!
Workspace: https://www.mediafire.com/file/jqz3tqcnha4j4jl/Villager_Trade_Tutorial_…

How did I do it?
1 - I used: gold and emerald 32x32 texture and a model of "Traveler Villager (made by me)"

2 - Create your Villager (Type: Creature / AI base: NONE)

3 - Create a procedure to check the item and change in the player's inventory:

If = Has provided entity (item for exchange) in inventory
do = Add "Value" (item result of exchange) to provided players
         inventory
         Remove "Value" (item for exchange) to provided players inventory

4 - Create a GUI using item textures (32x32) and a button to activate the exchange

5 - Finally, create a Procedure to open the GUI:

      Open GUI to provided player. GUI: (select the Villager GUI that
      you created)

We have reached the end of this tutorial, I hope I have helped!
Any questions, leave a comment!