Go to Admin menu > Structure > Display Modes > View Modes.
This list contains all of the different view modes that are associated with all of the different entities contained within the site.
Click the Add View Mode button to create a new View Mode.
You'll be redirected to the Choose View Mode Entity Type screen.
Click on the entity that you want to associate this View Mode with.
In our example, we're using the Media entity.
Name field = enter a name for the new entity.
Click the Save button.
You'll be redirected back to the View Mode list.
The new View Mode will be listed in its appropriate location.