Swim Script Not Work

[MR_M3WTWO (Mew)]

Its a simple swim script that’s just supposed to make the player float at the top and play an animation when in ‘Ocean’. It doesn’t work at all and was wondering if anyone can help.

local swimVelocity = nil
local swimming = false

local swimAnimation = script:WaitForChild("SwimAnimation")
local swimTrack = animator:LoadAnimation(swimAnimation)

uis.JumpRequest:Connect(function()
  if swimming and swimVelocity ~= nil then
    swimming = false
    swimVelocity.Position = Vector3.new(0, 20, 0)
    swimVelocity.MaxForce = Vector3.new(0, math.huge, 0)
    swimTrack:Stop()
    swimTrack.TimePosition = 0
    wait(0.7)
    swimVelocity:Destroy()
    swimVelocity = nil
    if not humanoid then return end
    humanoid.WalkSpeed = 24
  end
end)

local function swim(target)
  if swimming then return end
  -- Check if swimVelocity doesn't exist (is nil)
  if swimVelocity == nil then 
    swimming = true
    swimVelocity = Instance.new("BodyPosition")
    swimVelocity.Position = Vector3.new(0, 0, 0)
    swimVelocity.MaxForce = Vector3.new(0, math.huge, 0)
    swimVelocity.Parent = target
    if not humanoid then return end
    humanoid.WalkSpeed = 50
    swimTrack:Play()
  end
end

while true do
  runService.RenderStepped:Wait()
  local Torso = character:FindFirstChild("HumanoidRootPart")
  if Torso ~= nil then
    if (Torso.Position.Y < -10) and (swimming == false) then
      swim(Torso)
    else
      if (Torso.Position.Y > 0) and (swimming == true) then
        swimVelocity:Destroy()
        swimVelocity = nil
        swimming = false
        swimTrack:Stop()
        swimTrack.TimePosition = 0
      end
    end
  end
end

Thank You!