Foxit Reader has two toolbar modes. One is ribbon mode, the other is classic mode. You can change the toolbar mode in the application window depending on your current mode:
Ribbon Mode -> Classic Toolbar Mode: FILE > Change Toolbar Mode, or HELP > Change Toolbar Mode.
Classic Toolbar Mode -> Ribbon Mode: View > UI Options > Change Toolbar Mode.
Note: The Classic Toolbar Mode has been removed from the latest version 22.214.171.124.