If you hold a Canadian refugee travel document and are planning to travel to Asia with a transit in Hong Kong, you may need a transit visa. Whether or not you need a transit visa depends on the immigration laws and regulations of Hong Kong, as well as the specific details of your travel itinerary.
It's important to check the entry requirements for Hong Kong and any other countries you'll be transiting through or visiting, as they may have different rules and regulations. Some countries may require a transit visa even for short layovers, while others may allow visa-free transit for certain periods of time.
To determine whether you need a transit visa for Hong Kong, you can consult the Immigration Department of the Government of Hong Kong Special Administrative Region or a Hong Kong visa specialist. They will be able to advise you on the specific requirements for your travel document and itinerary.