Hello so the reason is to reunite with my spouse who is temporarily working in Canada. So I attached: my spouse's Work permit, her passport, temporarily work visa, my own passport, and our marriage certificate. I also included my quarantine plan, saying how I will be sleeping in the guest room for 14 days and have my spouse buy the groceries for me and I will not leave the house. I also mentioned that I will be staying in Canada long-term to live with my spouse.
Hope that helps you and good luck. The waiting time is quite frustrating since I was cutting so close to my desired travel date. I would suggest you apply as soon as possible.