"apply" button for settings

Can't find one. Apparently the only way to invoke a change is to hit the X button. Which is a pain if I want to look at alternatives. Maybe a keyboard shortcut?

Windows 10 uses the "new" approach to user interface. When you make changes in a non-modal settings window, they apply immediately, without waiting for you to hit any buttons. There's no need and no point in Apply button for such settings.

If you want to return to higher level settings window you hit the "back" arrow in the upper-left corner . If you want to leave settings altogether, you hit X.