You mean in routevn? You open the Title page in scene editor. Then, click the + button on the bottom right then select your background picture. Use Center transform position so it's now placed in the middle, click submit and it should appear. ദ്ദി(˵ •̀ ᴗ - ˵ ) ✧ if it doesn't, that means a black bg is actually included with the Title Layout, so you should change it in the Layouts directly!
