Inventory SWEP

[lua_error]

Hello guys, i tried to make a simple swep for derp inventory addon, but i don't know how to make swep at all. I never done it before.
I remade derp inventory and added a concommand to pickup entities.

When i tried pickup nothing happens.

I tried to make this:

if SERVER then
    AddCSLuaFile("shared.lua")
end


if CLIENT then
    SWEP.PrintName = "Inventory"
    SWEP.Slot = 1
    SWEP.SlotPos = 2
    SWEP.DrawAmmo = false
    SWEP.DrawCrosshair = false
end


SWEP.Base = "weapon_cs_base2"


SWEP.Author = ""
SWEP.Instructions = ""
SWEP.Contact = ""
SWEP.Purpose = ""
SWEP.IconLetter = ""


SWEP.ViewModelFOV = 62
SWEP.ViewModelFlip = false
SWEP.AnimPrefix     = "rpg"


SWEP.Spawnable = false
SWEP.AdminSpawnable = true
SWEP.Primary.ClipSize = -1
SWEP.Primary.DefaultClip = 0
SWEP.Primary.Automatic = false
SWEP.Primary.Ammo = ""


SWEP.Secondary.ClipSize = -1
SWEP.Secondary.DefaultClip = 0
SWEP.Secondary.Automatic = false
SWEP.Secondary.Ammo = ""


if CLIENT then
    SWEP.FrameVisible = false
end


function SWEP:Initialize()
    self:SetWeaponHoldType("normal")
end


function SWEP:Deploy()
    if SERVER then
        self.Owner:DrawViewModel(false)
        self.Owner:DrawWorldModel(false)
    end
end


function SWEP:PrimaryAttack()


    self.Weapon:SetNextPrimaryFire(CurTime() + 0.2)
    local trace = self.Owner:GetEyeTrace()


    if not ValidEntity(trace.Entity) then
        return
    end
    
    if self.Owner:EyePos():Distance(trace.HitPos) > 65 then
        return
    end
    
    if CLIENT then return end
    
    self:SendHoldType("pistol")
    
    timer.Simple(0.2, function(wep) if wep:IsValid() then wep:SendHoldType("normal") end end, self)
    
    ConCommand("say drp_pickupitem")
    
    
end


function SWEP:SecondaryAttack()
    if CLIENT then return end
    self:SendHoldType("pistol")
    
    timer.Simple(0.2, function(wep) if wep:IsValid() then wep:SendHoldType("normal") end end, self)
    self.Weapon:SetNextSecondaryFire(CurTime() + 0.2)
    
    ConCommand("drp_showinv")

end