Adding weapons to pointshop

I have a SRCDS gmod server with pointshop installed. I tried to add a weapon in the shop. The weapon is in the shop but if you try to purchase it it just takes the points and doesnt give you the weapon. all i did was add this code in the weapon shop :
ITEM.Name = ‘Davy Crockett’
ITEM.Price = 1000000
ITEM.Model = ‘models/weapons/w_RL7.mdl’
ITEM.WeaponClass = ‘davy_crockett’
ITEM.SingleUse = true

function ITEM:OnBuy(ply)

function ITEM:OnSell(ply)

Is there a step im missing?

Is davy_crockett and valid weapon class?

you know what probably not. where can i find weapon classes?

In lua/weapons, gamemodes/(gamemodename)/entities/weapons, or addons/(addonname)/lua/weapons.