To run simply join the game, inject the script, select the NPC or ALL switch, select the weapon to use, and then click start:
Code:
loadstring(game:HttpGetAsync("https://pastebin.com/raw/6TW7RGz3"))()

local player = game:GetService("Players").LocalPlayer
local heartbeat = game:GetService("RunService").Heartbeat
local remotes = game:GetService("ReplicatedStorage").RemoteEvents
local btn, run
local current_array_index = 1

local gui = library:AddWindow("Project XL | Auto Farm (HamstaGang)", {
    main_color = Color3.fromRGB(69, 69, 69), -- ( ͡° ͜ʖ ͡°)
    min_size = Vector2.new(370, 310),
    can_resize = false
})

local all_array = { -- For our all switch
   "Bandits",
   "Rahgan's Overseers",
   "Agni's Overseers",
   "Lars' Minion",
   "Agni's Minions",
   "Rahgan's Minions"
}

local array = {
   ["Bandits"] = "Defeat 10 Bandits",
   ["Rahgan's Overseers"] = "Defeat 4 of Rahgan's Overseers",
   ["Agni's Overseers"] = "Defeat 6 of Agni's Overseers",
   ["Lars' Minion"] = "Defeat 8 of Lars' Minions",
   ["Agni's Minions"] = "Defeat 9 of Agni's Minions",
   ["Rahgan's Minions"] = "Defeat 7 of Rahgan's Minions"

}

local tab = gui:AddTab("Main")

tab:AddLabel("NPC")
local drop = tab:AddDropdown("Select", function(opt) array.target = opt array.quest = opt array.all = false end)
for i,v in next, array do drop:Add(i) end

local switch = tab:AddSwitch("All", function(opt) array.target = "ALL" array.quest = "ALL" array.all = opt end)

tab:AddLabel("Weapon")
local drop2 = tab:AddDropdown("Select", function(opt) array.weap = opt end)

repeat wait() until player.Backpack:FindFirstChildWhichIsA("BackpackItem") -- Wait for tools

for i,v in next, player.Backpack:children() do
    if v.ClassName == "Tool" then
        drop2:Add(v)
    end
end

btn = tab:AddButton("Start", function()
    if not array.farm then
        run = game:GetService("RunService").Stepped:connect(function()
            pcall(function() player.Character.Humanoid:ChangeState(11) end)
            pcall(function() game:GetService("Players").LocalPlayer.Head.Overhead.Player:Destroy() end)
        end)
        array.farm = true btn.Text = "Stop"
    else
        array.farm = false btn.Text = "Start"
        run:Disconnect()
    end
end)

library:FormatWindows()
tab:Show()

player.Idled:connect(function()
    game:GetService("VirtualUser"):ClickButton2(Vector2.new())
end)

coroutine.wrap(function()
    while wait() do
        if array.farm and not game:GetService("Players").LocalPlayer.PlayerGui:WaitForChild("Menu"):WaitForChild("QuestFrame").Visible then
            pcall(function()
                game:GetService("ReplicatedStorage").RemoteEvents.ChangeQuestRemote:FireServer(game:GetService("ReplicatedStorage").Quests[array[array.quest]])
            end)
        end
    end
end)()

while wait() do
    if array.farm then
        if array.target == "ALL" or array.all then array.target = all_array[current_array_index] array.quest = all_array[current_array_index] end
        spawn(function() pcall(function() player.Character.Humanoid:EquipTool(player.Backpack:WaitForChild(array.weap, 0.3)) end) end)
        for i,x in pairs(game:GetService("Workspace").Live[array.target]:GetDescendants()) do
            if player.Character:FindFirstChild("Humanoid").Health <= 0 then -- ded
                wait(8) -- Give time to respawn
                break;
            end
            if x.Name == "Humanoid" then
                if x.Health > 0 then
                    while x ~= nil and x.Health > 0 and array.farm and player.Character:FindFirstChild("Humanoid").Health > 0 do
                        repeat wait() until player.Character:FindFirstChildWhichIsA("BackpackItem")
                        setsimulationradius(math.huge,math.huge)
                        player.Character:WaitForChild("HumanoidRootPart", 15).CFrame = (x.Parent.HumanoidRootPart.CFrame * CFrame.new(0,-7,0)) * CFrame.Angles(80,0,0)
                        wait(0.3)
                        game:GetService("ReplicatedStorage").RemoteEvents.BladeCombatRemote:FireServer(true, nil, nil)
                        wait(0.3)
                        x.Health = 0
                        heartbeat:wait()
                    end
                end
            end
        end
        if current_array_index == 5 then current_array_index = 1; else current_array_index = current_array_index+1; end
    end
end