GET UniqueID 404 (Not Found)

[Buffett06425]

Hi，

I'm sorry for the inconvenience.
I've been practicing using the drawtogether example recently, but I encountered the following error when trying to navigate to exp.html.
(I establish VM on EC2)

GET https://my_domain/sync/%7B%7B%20uniqueId%20%7D%7D 404 (Not Found)

	send	@	jquery-2.2.4.min.js:4
	ajax	@	jquery-2.2.4.min.js:4
	a.ajax	@	backbone-min.js:1
	a.sync	@	backbone-min.js:1
	sync	@	backbone-min.js:1
	fetch	@	backbone-min.js:1
	PsiTurk	@	psiturk.js:326
	(匿名)	@	task.js:8

Can help me with the question?
thanks