In Objects and Animation click on (highlight) the object/image that you wish to apply Pan (or Zoom / Rotate) to.

Note the Pan and Zoom parameters above: Pan = Zero; Zoom = 640×360 (In Pixels Mode)

Right Click on the Key Frame on the extreme left of the timeline and choose “Add Key Frame” from the menu.

A new (Blank) Key Frame is created at the Full Slide Duration:

Change the Pan (horizontal) from minus 50 to plus 50.

Press Play. The Object moves from its original position (-50) to its new position (50) in 7 seconds (Key Frame Time = 7000ms). Any combination of Pan, Zoom and Rotate (PZR) can be combined in the same Key Frame. The SPEED of the animation is governed by the time between the Key Frames.