My custom items keep disappearing please help

So I used this command loottable.backup create to back up some of my items but it only backed up the loot 

is there a way to back up my custom items because every time my server resets the items that are custom go away

custom items are not included in backups

you have to manually make a copy of the custom items file in the loottable data folder

So where do I find that file that I need to enter all my custom items manually?

thank you for answering and helping me out

is it this file here custom_items_v2

and how will I be able to update it loaded back in the plug in

yeah its custom_items_v2.json

just make sure the plugin is unloaded when you paste your backup file