You would need to apply for the Canadian match- there should be instructions on the CaRMS website for foreign MD grads. The issue is that depending on the year, the Canadian match is usually before the US match and if you matched in Canada you would have to commit to wherever you matched without knowing where you matched in the US. A few schools take a US student or two each year (McGill usually has a couple), but they tend to be top tier MD/PhD type people with tons of research. Even if you do match, do you really want to be a physician in Canada? I say this as someone who lived there for 6 years- it’s a much better gig to be a doc in the US