Setting Logo Link on Topbar?

I’m creating an external landing page for my company’s Holiday promotions. I’m trying to set the Topbar so that our company logo links back to our main site ( instead of the promotion home page.

I set a dropzone on the right so I can place a button to link them back to the main promotion landing page, but I can’t seem to find any settings to change what the logo itself links to. I can only find it if I inspect the element in Chrome.

Any ideas?