How can I add ammo to the pointshop?

I have code It would work but the icon in the pointshop does not show up. Does anyone know of a different way to do it?


ITEM.Name = '7.62ammo'
ITEM.Price = 18
ITEM.Model = 'models/nordahlammo/boxmrounds.mdl'
ITEM.SingleUse = true
ITEM.NoPreview = false
 
function ITEM:OnBuy(ply, tr)
        if (!tr.Hit) then return end
       
        local SpawnPos = tr.HitPos + tr.HitNormal * 16
       
        local ent = ents.Create("zmod_ammo_762nato")
                ent:SetPos(SpawnPos)
        ent:Spawn()
        ent:Activate()
       self.Entity:SetMaterial("nordahl/n762mm.vmt")
        
		return ent
end

Sorry for bumping this thread, but I need help with this problem too.