Newb crafting custom item

[hlw]

Can anyone provide guidance on crafting the following:

Cartouche of Solidarity: This item has 4 charges that recharge after a long rest. Those charges allow you to take an extra reaction for the price of one charge. You also add double your proficiency bonus to initiative rolls, and have resistance to radiant damage.

Thanks!

[dungeonguru]

Although I personally think the Initiative piece of this item is way overpowered, you simply need to:
Get into the editor.
Go to the Equipment tab,
Select the Wondrous sub-tab
Choose New (Blank) at the bottom left.

Give it a name
Give it a Unique ID
Fill in the description
Go down the fields and give it a rarity? Check or Uncheck the Attunement options.
Further down find the Charge Information section,
type in 4 for base charges.
Find and select /day or /longrest for Usage Period?
If you want it on the tracked resources section, check the Show in Tracked Resources list? option.

Now the trickier part. On the upper right you will see an Eval Scripts button. Click the button.
Click where it says to add another eval script.
Some new stuff will show up, so
In Phase, choose Post-Levels
In Priority type 10000
Copy/Paste the following into the Script area:

      doneif (field[gIsEquip].value = 0)
      doneif (field[gIsAttuned].value = 0)

      perform hero.assign[DamageRes.dtRadiant]
      hero.child[Initiative].field[Bonus].value += hero.child[ProfBonus].field[tProfBonus].value + hero.child[ProfBonus].field[tProfBonus].value

I'm going to gloss over everything but the first two lines. If you don't have to equip the item, remove the first doneif. If you don't have to attune the item, remove the second doneif.