Tablet as item

If you want the tablet to work as an item, you need to create the item based on the inventory script you're using.

ox_inventory

File Location: ox_inventory/data/items.lua

Image Should Be placed in: ox_inventory/web/images

["courier_tablet"] = {
    label = "Courier Tablet",
    weight = 1000,
    client = {
      event = "op-courier:openCourierTablet",
    }
},

qb-inventory

File Location: qb-core/shared/items.lua

Image Should Be placed in: qb-inventory/html/images

courier_tablet = {
    name = "courier_tablet",
    label = "Courier Tablet",
    weight = 1000,
    type = 'item', 
    image = 'courier_tablet.png', -- Optional, if you want an image for it
    useable = true, 
    shouldClose = true, 
    client = {
      event = "op-courier:openCourierTablet",
    }
 },

Basic ESX

This is MySql insert.

INSERT INTO `items`(`name`, `label`, `weight`, `rare`, `can_remove`) VALUES ("courier_tablet", "Courier Tablet", 1, 0, 1)

quasar_inventory

['courier_tablet'] = {
    name = 'courier_tablet',
    label = 'Courier Tablet',
    weight = 5,
    type = 'item',
    image = 'courier_tablet.png', -- Optional, if you want an image for it,
    unique = false,
    useable = true,
    description = 'A tablet for courier job related tasks.',
    client = {
        export = 'op-courier.openCourierTablet'
    },
}

Optional Image: