According to the IRCC site, Canadian work permit fees amount to CAD 155 per person. Pay your fees when you apply. You will be instructed to pay all your open work permit fees during your application process. In order to be able to make a payment online, you have to have a:
A PDF Reader;
A printer
A valid email address
A credit or debit card
Payment should be made after you have applied. Note that if you have not been asked to pay an open work permit holder fee when you have submitted your application, you should still make the payment online.