Jumping problem!

[TF_Killer (Nezui)]

hi , im trying to make jumping script follow this tutorial but its acting wried

Math for Game Developers - Jumping and Gravity (Time Delta, Game Loop)

heres my script

local module = {}

function module:Setting(target, velocity)
    module.__index = module
    self.Target = target
    self.Position = target.Position
    self.velocity = velocity
end

function module:Jump(dt)
    local gravity = Vector3.new(0, 3, 0)
    print(gravity)
    self.Position = self.Position + self.velocity * dt
    self.velocity = self.velocity + gravity * dt
    warn(self.Position + self.velocity)

    return self.Position, self.velocity
end

return module

server
local Part = workspace.Part;
local Jump = require(script:WaitForChild("jump"));

Jump:Setting(Part,Vector3.new())

game:GetService("RunService").Heartbeat:Connect(function(dt)
local pos,velo = Jump:Jump(dt)
Part.CFrame = 	CFrame.new(pos)
Part.Velocity = velo
end)

and this happened
https://streamable.com/1wziup