1) 60 days? Not 90 days to submit profile with documents?
2) Also, do I need to do something to "accept" the ITA? I assume I "accept" the ITA if I do not decline it. Please clarify this. Thanks
1- yes you are right it is 90 days, You would receive a message as follows Literally,
"You should immediately start gathering all the supporting documents and information you need to include on your application so that you can submit your application within the 90-day deadline. Please note that some documents, such as police certificates, may take some effort and time to acquire so begin gathering these documents now. If, at the 90-day deadline, any of the supporting documentation and information is missing and you do not have a valid reason, your application will be rejected.".
2- yes you need to do. In practice once you login to your IRCC account you will see a statement of ITA and two activity options Continue meaning accept ITA or decline. Be careful not to press decline by mistake.
This feature would last only for 30 days otherwise it will be automatically declined and route you back to the pool.