Add submenu below your main menu navigation of your PremiumPress Responsive Theme with the help of this WordPress plugin.
1) Install and activate the plugin
2) in admin > Appearance > Menus – create/select your menu and assign it to the ‘Sub Menu’ location.
3) If desired, style to match your design.
* Fixed issue of menu not wrapping correctly on mobiles (responsiveness)
* Fixed compatibility issue with themes v6.5+