This is a setting that must be implemented or overridden by the application.
The Microsoft page says the following about his subject.
Ensure that UI elements that can be clicked can also be invoked by
using the keyboard. To use the keyboard with a UI element, the element
must have focus. Only classes that derive from Control support focus
and tab navigation.
For UI elements that can be invoked, implement keyboard event handlers
for the Spacebar and Enter keys. This makes the basic keyboard
accessibility support complete and enables users to accomplish basic
app scenarios by using only the keyboard; that is, users can reach all
interactive UI elements and activate the default functionality.
In cases where an element that you want to use in the UI cannot have
focus, you could create your own custom control. You must set the
IsTabStop property to true to enable focus and you must provide a
visual indication of the focused state by using the VisualStateManager
class. However, it is often easier to use control composition so that
the support for tab stops, focus, and Microsoft UI Automation peers
and patterns are handled by the control within which you choose to
compose your content.
We can conclude 3 things
The UI element must have focus
The app can override the default and make it impossible to support the keyboard
Accessibility is relevant, if you could press enter then the app would not have accessibility support. And we know there is accessibility support in Windows.
We know that the application has accessibility support. Try to search for some of these options.