can I use a different domain as my site address?

I have a website which is residing on a .com domain. My hosting company does not handle .ca domains, so we have a .ca domain forwarded to the .com address.

For google/SEO purposes, they would like to have the .ca address as the main domain. Can I just change the site address in settings to have it appear as if it’s on the .ca domain? I’m a bit scared to try it to see what happens. I know you can do this if it’s inside a folder on the same domain, but not sure about using another one altogether.

Thanks for your help!