You can get a mortgage from BMO by contacting the bank directly. You can get or by getting in touch with a BMO approved mortgage broker. The alternative to getting a mortgage directly from BMO is to work with a mortgage broker.
Using a broker comes with a few advantages. A mortgage broker gives you the added benefit of being able to compare mortgage rates and products between different lenders, as well as the chance to speak to an independent mortgage expert. If a given lender does not work with brokers, it might still be worth speaking to one to see what else is available in the market.