Problem with zipline script that makes no sense for me?

So here I have this poorly made script (Because i'm bad at scripting)

Anyway, When I test it, it says that bodyposition is not a valid member of Dabbingston (dabbingston is a Union part) and i don't know what to do

If you could help me out, that would be great

local model = script.Parent.Parent -- this is just a model
local platform = model.platform -- this is a seat, if you could mix this with dabbingston and make it function like a real zipline I'd be very happy
local deco = model.Dabbingston -- this is a union
local start = model.start -- this is just a brick, same for finish
local finish = model.finish
local bodyPos = platform.BodyPosition
local Dbodypos = deco.BodyPostion --  this is where it gives the error
local time = 2 --Time between motion

while true do
	bodyPos.position = start.Position
	Dbodypos.position = start.Position
	wait(time)
	bodyPos.position = finish.Position
	Dbodypos.position = finish.Position
	wait(time)
end

On line 4 write:

local BP = Instance.new("BodyPosition", deco)

This is erroring because there is no "BodyPosition" in "deco" and it is looking for something that is not there. The error is pretty self-explanitory but ye you just need to put a bodyposition in there.