the error is ''Position is not a valid member of Model'', when i go check it it goes into line 15?

local Molly = script.Parent
local humanoid = Molly.Humanoid

local PathfinderServise = game:GetService("PathfindingService")

local function getPath(destination)
    local pathParams = {
        ['AgentHeight'] = 6,
        ['AgentRadius'] = 2,
        ['AgentCanJump'] = false

    }
    local path = PathfinderServise:CreatePath(pathParams)

    path:ComputeAsync(Molly.HumanoidRootPart.Position, destination.Position)

    return path 
end

local function walkTo(destination)
    local path = getPath(destination)

    for index, waypoint in pairs(path:GetWaypoints()) do
        humanoid:MoveTo(waypoint.Position)
        humanoid.MoveToFinished:Wait()
    end
end

local function patrol()
    local waypoints = workspace:GetChildren()
    local randomNum = math.random(1, #waypoints)
    walkTo(waypoints[randomNum])
end

while wait(2) do
    patrol()    
end