You can add a logo or any other text to the home page of your Bugzilla.
Log into the devZing account – https://devzing.com/login
Choose “Front Page” from the Bugzilla menu.
Add some HTML that will show your logo or welcome message to the “Enter some HTML that will appear below the welcome message” box.
<img src="https://example.com/img/logo.png" />
Be sure to use “https” and not “http” in your urls so you don’t get an “insecure url” warning.