Hong Kong travel visa for Vietnam passport holder living in Toronto

Minh, you can apply for HK entry permit at the consulate general of PRC or apply for it from HK immigration department directly.
If you submit your application to the consulate and it deals with your application on its own, it usually takes 4 working days and costs CAD50; but if your application is transferred to HK immigration department or you post your application there direct, it will take 4 to 6 weeks and costs HKD100 if you apply for transit entry permit. Please note that you also need to pay CAD50 to the consulate general for communication fee.
There is no VOA in HK.