Here at the bottom of the page you can find the location where to send your application. As you are applying from outside Canada, you would send it to CPC-Sydney, like I did
https://www.canada.ca/en/immigratio...-guide-sponsor-your-spouse-partner-child.html
The address is:
Sending by mail - Application for spouses, common-law partners or conjugal partners currently living outside Canada and all dependent child sponsorships:
Case Processing Centre - Sydney
P.O. Box 9500
Sydney, NS
B1P 0H5
Sending through courier service - Application for spouses, common-law partners or conjugal partners currently living outside Canada and all dependent child sponsorships:
Case Processing Centre - Sydney
49 Dorchester Street
Sydney, NS
B1P 5Z2