To edit the slideshow, you need to use the timeline (1), the slide view (2) and the property panel (3). o open the properties panel, use the button in the toolbar (4).
Create slide
When creating a new project, the slideshow contains one slide (nammed ‘Slide-1’) that occupies the whole duration.
To add a slide:
Move the playhead to the position of the the new slide.
Use the button on the toolbar.
A new slide is created at the position of playhead.
You cannot create two slides less than 1 second apart.
Delete slide
To delete a slide:
Move the playhead on the slide by clicking on the time ruler with ALT or by clicking on the playhead and dragging.
Use Edit > Delete Current Slide menu.
You cannot delete the first slide.
Edit slide
The properties of the slide under the playhead are displayed in the right panel. Move the playhead to display the properties of the other slides:
Ratio of the slides: This setting impacts all the slideshow.
Title, start time and duration. To change duration of a slide, change start time of the next slide. You cannot change start time of the first slide.
You also can change time start by clicking and dragging the beginning of slide in the timeline.
Change background color, image and video (you need to import image and video before).
Change horizontal and vertical offset, zoom, and edit image.