回复：请教:加移民如何免考英文? 在美读博即将毕业,有美国家级论文奖

My suggestion:

Write a letter to explain why you think you do not need to take that eaxm and send it with your supporting materials such as your English paper to demonstrate your master of English. Get a native English person to polish your letter.

I have no experience with Canada immigration stuff.

Just a suggestion.