Creating Legendary items

Hi I am new to using this plugin. I created a legendary armor item and I can spawn it in a loot container(vanilla default loot) in the config json file. My question is what is the command to give that certain Item ID to my inventory with not having to spawn in a crate to see if item is in the crate and pick it out of case.  I am also using the plugin Loot Table & Stacks GUI. I am trying to find how you add the Legendary Items with the buffs in the loot tables. I keep reading forums you need an API to edit the plugin custom items to the custom loot table. Is it possible to find the Custom Legendary Item short name ID number? So i can spawn that number id in a loot table to get that exact item with the correct buffs?  Is there a plugin that shows you the list of all your custom item ids to spawn in?

This is the loot plugin I am using, that I am trying to add the Legend items to the custom loot tables.

What is the exact command to type in F1 to give myself a custom item. I'm doing givelegendary Sergeant Helm then enter. nothing happens.
Idk what im doing wrong.

OK this is my code of my helm i created.
 

 "Sergeant Helm": {
      "Item shortname": "metal.facemask",
      "Item skin": 3322501158,
      "Restrict enhancement": true,
      "Announce in chat when this item drops for the player?": false,
      "Send a UINotify message to the player when this item drops?": false,
      "List of perks and modifiers that the item has [perk: modifier]": {
        "UncannyDodge": 0.16,
        "FlakJacket": 0.1,
        "Thorns": 0.05
      },
      "Description about the item that is shown when mousing over the ownership banner [blank/null = nothing]": null,
      "How many armor mod slots will the item spawn with? [won't exceed item definitions max cap]": 4
    },

What is the command I type in the F1 console in-game to spawn this item in my inventory?  Other than spawning tons of crates and hoping I find one. Is the option to spawn in this item available?  Reason why I ask, say someone on the server loses an item and asks to be reimbursed the item, how do I spawn in a replacement item.