UDesign supports sidebar as a widget area. You can create a widget area in UDesign > Sidebars like followings.

Step 1 : Click the ‘Add New Sidebar’ button for new widget area.

Step 2 : Input you custom widget area name on the appeared modal and click the ‘OK’ button.

Step 3 : To see widget area, please visit Appearance > Widgets in admin’s main menu.