Method 1
Simply drag and drop the bar in the Sections List to move its place in your presentation.
Method 2
Hover on the Section space and click on the 4-directional arrow icon to drag the Section up or down in the Presentation.
Learn two ways to move a section in a presentation: drag the section from the Sections List, or use the 4-directional arrow icon to reposition the section directly in the presentation layout.