Reddit Roblox LUA Help Guide

-- Practice proper naming.
local Players = game:GetService("Players")
local Humanoid = script.Parent.Enemy
-- Just use Once if you'll just remove the script after the Humanoid died.
Humanoid.Died:Once(function()
    local getPlayers = Players:GetPlayers() -- a collection of players.
    for _, plr in pairs(getPlayers) do
        local getLeaderstats = plr:FindFirstChild("leaderstats") -- lets check if leaderstats is available
        if getLeaderstats then
            local Coins = getLeaderstats:FindFirstChild("Coins") -- check if Coins is available inside the leaderstats.
            if Coins then
                Coins.Value = Coins.Value + math.random(3, 5)
            end
        end
    end
    -- remove the script after done.
    script:remove()
end)