Starting from 1st October 2022, travellers entering Canada are not required to provide proof of COVID-19 vaccination. It is also not compulsory for travellers to undergo COVID-19 pre-boarding, pre-entry and arrival tests as well as quarantine upon arrival.
Though it is not legally required for travellers to wear masks during travel, it is highly recommended to wear a well-constructed and well-fitted mask or respirator during your journey.
However, it is best to remember that the travel situation post Covid-19 is constantly evolving. Make sure to refer to Government of Canada's webpage for latest updates on the post Covid-19 travel situation.
Singapore’s Ministry of Foreign Affairs website also provides a comprehensive guide in regard to travelling abroad, especially to Canada.