All monetizing creators on YouTube, regardless of their location in the world, are required to provide tax info to Google. Google may begin withholding U.S. tax on your earnings as soon as June 2021. Google is requesting your tax information by May 31, 2021. Canada and the United States have a Tax Treaty to reduce double taxation.
Google will request a foreign TIN (taxpayer identification number) or U.S. TIN from you. Your foreign TIN is your Canadian Social Insurance Number. If you prefer, you can apply for U.S. individual taxpayer identification number by completing a Form W-7.
Click on the link for the Form-W-7: https://www.irs.gov/pub/irs-pdf/fw7.pdf
If Google deducts income tax from your earnings, you should be able to claim those withholding taxes as a credit against your Canadian taxes.