How do I clone a tool into a players backpack? [Solved]

I'm trying to clone a tool from ReplicatedStorage into a players backpack with a command

when I type the command in the script runs through but the receiving player doesn't get the tool.

Here is the script:

commands.give = function(sender, arguments)

    print("Give Classup command fired by "..sender.Name) 

    local playerToGiveClassupTo = arguments[1]
    local toolToGiveToPlayer = arguments[2]

    if playerToGiveClassupTo then
        local plr = findPlayer(playerToGiveClassupTo)

        if plr then 
            local backpack = plr:WaitForChild("Backpack")
            local cloneTool = game.ReplicatedStorage.classup:Clone()

            cloneTool = plr.Backpack
            print(playerToGiveClassupTo.." was given ".. toolToGiveToPlayer) 

        end
    end
end

there aren't any errors in the output but no tool is in my inventory.

the command is ":give (Player name) classup" and the tool "classup" is in ReplicatedStorage.

any solutions?

edit: also this is just a section of the script showing this command only. all my other command scripts work fine.