sorry i don speak english.
when new users enter the server, they do not have the backpack item, supposedly it is configured so that yes:
ItemShortcut:

If enabled the players will be given an item they can interact with to open the backpack.

The item may not be removed from their inventory as long as this option is enabled.

Enabled: true

I think it's only for admins the item in the inventory :( and I want everyone to have the item, including non-administrators.
I want help, sure it's very easy but I don't know.
thank U and greetings from Argentina.

Your users need to have the backpack.use permission in order to be able to use the plugin. If you don't have a permission plugin you can check this.