Oh no!  You can generally find your SIN number on your tax return, tax slips, record of employment, or RRSP contribution.

If you STILL can not find your SIN you will have to submit an application here:

https://www.canada.ca/en/employment-social-development/services/sin/apply.html

However, due to the labour disruption there will be delays in the application process.  Hope this helps!