Can any Confluence user see a Canva invitation, business cards, flyers, lesson plans, Zoom backgrounds without having a Canva account?

Yes. The information provided by Canva allows the users to see the graphic design without being logged in to Canva.

Can I embed invitations, business cards, flyers, lesson plans, Zoom backgrounds with a free account?

Yes, users with a Canva account can embed invitations, business cards, flyers, lesson plans, Zoom backgrounds in all available modes.

Can I embed Canva invitations, business cards, flyers, lesson plans, Zoom backgrounds without a Canva account?

Yes, users with no Canva account can also embed Canva invitations, business cards, flyers, lesson plans, Zoom backgrounds as long as they have the links to the boards.

The command /Canva is triggering a different Canva app.

It can happen that different apps are called typing the /Canva command if they are installed at the same time in Confluence. Make sure to select Canva for Confluence from the dropdown menu. Alternatively, you can look for the app using the Macro menu.