The 60-days timeframe is a strict rule. You can not extend that. If you are unable to meet that deadline, then you can decline an invitation. You will be put back into the Express Entry pool of candidates and considered in future rounds (if you are still eligible). Please note that declining an invitation will not affect whether or not you are invited to apply later, as long as your score is high enough to get invited. However, if you don't decline an invitation and you don't apply within 60 days, the invitation will expire, and your profile will be removed from the pool. You will have to start over again.
How can I apply for an extension if I cannot submit my full application within 60 days of being selected by Canada?
I just submitted my application online to enter the Express Entry pool of Canada. I understand that I would be notified once my application is drawn, and I will have 60 days to submit my full application. In cases that the applicants could not submit their full application in the required timeline, is it possible to apply for an extension?