If I may, I would offer this. Under the Customs Act, you have to present to the nearest customs office, and Gilles is right in his characterization of it. For the purpose of an asylum claim, the manner in which you got to Canada is totally irrelevant. In the context of failed refugee claimants, what would apply is the conditional removal order they are issued when they make their claim until the process is resolved.
On May 3rd, 2018. See this statement in context.