As of 12:01 a.m. EST on January 5, all air travellers who are two years of age and older, arriving on flights originating from the People’s Republic of China, Hong Kong or Macao, will need to provide evidence of a negative COVID-19 test result, taken no more than two days before their departure, to the airline prior to boarding. The test could be either a negative molecular (such as a PCR test), or a negative antigen test that has documentation to show that it has been monitored by a telehealth service or an accredited laboratory or testing provider. Passengers who tested positive more than 10 days before their departure flight, but no more than 90 days, can provide the airline with documentation of their prior positive, in place of a negative test result.

Read more at https://www.canada.ca/en/public-health/news/2022/12/government-of-canada-announces-negative-covid-19-test-requirement-for-travellers-arriving-from-the-peoples-republic-of-china-hong-kong-or-macao-air.html