Click the Profile icon that is located at the top right of any page and under the Information section, there is a field labeled 'Company Logo:'.
The Company Logo once added will be added in a few places on your ProxioPro account:
-at the bottom of your listings under the Office Information
-when you create a 'Client Report', which also can be performed through the Publication left menu or on any other listing in Proxio
-when a flyer is created - navigate using the left menu to PUBLICATION > Publication (many KW users will have a top menu and will navigate to Home > under Listing Tools click on the ADVERTISE A LISTING).