For accounts with a customized Contacts View, the app ribbon is a thin bar on the right as shown in the below image:
However, the normal view for this should fill up ⅔ of the screen:
This article will show you how to convert the one-third view to the two-thirds view as
NOTE: When the app ribbon view is changed to two-thirds, the main panel shrinks. For screens not optimized to work on mobile (responsive), the display will not optimally fit inside this. Designing a screen to be responsive is beyond the scope of this document, but to get you started, please see our help article "Responsive Design".
Enable Full Two-Thirds App Ribbon View
In this example, we will change the View Contacts screen to display the app ribbon in a full two-thirds view.
1. Customize your screen. If prompted to copy your screen or create a new version, click Yes.
2. On the right properties panel, click the page icon to go to the screen's properties.
3. You will find a dropdown called App Ribbon. Select 2/3 Panel.
4. Save the screen, and you're done!
If you need help to test this out, you can reach out to our Professional Services team for support with this.