Am I stupid or what? I am trying to understand how to add a new UNIQUE vending profile to use with another plugin after that, not to break/edit one of my vanilla vending. I do not want to modify my current monument vending machines. I want to make a completely new profile.

Which plugin? Other plugins should handle this automatically. They will register a vending machine as custom and override the place where the data is saved to and retrieved from, while still allowing you to edit the vending machine in game. The documentation of those plugins should hopefully guide you on this.

If the plugin is Talking NPC Vendors, there will be commands to create vending profiles for a given vendor. Those will create data files under that plugin's data folder.

Yeah, thanks for the help, issue is solved. I was wondering if have to place a new vending with Monument Addons and then use it as a new profile but looks like other plugins "in my case Talking NPC Vendors" do this by themselves. Only listed items do not show the SkinID icon, ideas why?