The Call to Action button allows you to add a button in your virtual event hub navigation, wherein you can link that button to redirect to a specified URL.
Add a Call to Action Button
Go to the Event Design tab of your admin console, select Event Hub, then click on Navigation
Scroll down and enable the toggle for Call to Action Button
Paste in your Call to Action URL
Click Choose File to upload an image for your Call to Action button (210 x 70 pixels - Ratio 3:1)
That's it! The button should appear at the bottom of the left-side navigation in the event hub. When the button is clicked, it will redirect to the URL you indicated.