Error when making a possession script, isnt reaching the second OnServerInvoke?

So I have this possession script, its activated when clicking on a player and you possess their character but as a result you lose your original character so theres an empty clone there for you to inhabit after you depossess by pressing R when youre in the other players possessed body, the depossession phase i cant reach though because i have a strange error but first im gonna show all the scripts

localscript in starterplayerscripts

local Players = game:GetService("Players")
local ReplicatedStorage = game:GetService("ReplicatedStorage")
local UserInputService = game:GetService("UserInputService")

local Player = Players.LocalPlayer
local Mouse = Player:GetMouse()

UserInputService.InputEnded:Connect(function(input)
    if input.UserInputType == Enum.UserInputType.Keyboard and input.KeyCode == Enum.KeyCode.R then
        ReplicatedStorage.ReturnPossession:InvokeServer()


    end
    if input.UserInputType ~= Enum.UserInputType.MouseButton1 and Mouse.Target then
        local targetPlayer = Players:GetPlayerFromCharacter(Mouse.Target.Parent)
        if not targetPlayer then return end

        local result = ReplicatedStorage.TakePossession:InvokeServer(targetPlayer)
        if result then
            print(result.Error)

        end
    end
end)


ReplicatedStorage.EnableClientControls.OnClientEvent:Connect(function(enable)
    local controls = require(Player.PlayerScripts.PlayerModule):GetControls()
    if enable then
        controls:Enable(true)
    else
        controls:Disable()
    end
end)

serverscript in serverscriptservice

local ReplicatedStorage = game:GetService("ReplicatedStorage")

local IS_POSSESSED_KEY = "IsPossessed"
local IS_POSSESSING_KEY = "IsPossessing"
local RETURN_CHARACTER_KEY = "ReturnCharacter"

function updateReturnToCharacterValue(character, parent)
    local value = nil
    if parent:FindFirstChild(RETURN_CHARACTER_KEY) then
        value = parent[RETURN_CHARACTER_KEY]
    else
        value = Instance.new("ObjectValue")
        value.Name = RETURN_CHARACTER_KEY
        value.Parent = parent
    end
    value.Value = character
end

ReplicatedStorage.TakePossession.OnServerInvoke = function(player, target)
    if not target:IsA("Player") then
        return {
            Error = "Target is not a player"
        }
    end

    if player == target then
        return {
            Error = "You cannot possess yourself"
        }
    end

    if player:GetAttribute(IS_POSSESSED_KEY) then
        return {
            Error = "You are already possessed"
        }
    end

    if player:GetAttribute(IS_POSSESSING_KEY) then
        return {
            Error = "You are already possessing someone else"
        }
    end

    if target:GetAttribute(IS_POSSESSED_KEY) then
        return {
            Error = target.DisplayName .. " is already possessed"
        }
    end

    if target:GetAttribute(IS_POSSESSING_KEY) then
        return {
            Error = target.DisplayName .. " is already possessing someone else"
        }
    end

    -- Clone original character and reassign character
    -- (clone is required because character is deleted after Character reassignment)
    local originalCharacter = player.Character
    originalCharacter.Archivable = true
    local originalCharacterClone = originalCharacter:Clone()
    originalCharacterClone.Parent = originalCharacter.Parent
    updateReturnToCharacterValue(originalCharacterClone, player)

    -- Assume ownership of the target
    local targetCharacter = target.Character
    targetCharacter.HumanoidRootPart:SetNetworkOwner(player)
    player.Character = targetCharacter

    -- Tell the posessed player to seize controls
    ReplicatedStorage.EnableClientControls:FireClient(target, false)


    --------RETURN POSSESSION
    game.ReplicatedStorage.ReturnPossession.OnServerInvoke()

    --possessed player receives back controls
    ReplicatedStorage.EnableClientControls:FireClient(target, true)

    --Possessors ownership of target is revoked 
    player.Character = player[RETURN_CHARACTER_KEY].Value




    -- Set info on player and target
    player:SetAttribute(IS_POSSESSED_KEY, false)
    player:SetAttribute(IS_POSSESSING_KEY, true)

    target:SetAttribute(IS_POSSESSED_KEY, true)
    target:SetAttribute(IS_POSSESSING_KEY, false)
end

now the error is "OnServerInvoke is a callback member of RemoteFunction; you can only set the callback value, get is not available."

and it says this error on line 19 in the localscript

local result = ReplicatedStorage.TakePossession:InvokeServer(targetPlayer)

No idea what it could possibly mean but its preventing my goal of the player being able to depossess