Task: I would like to use the wps office  app to add the first video from videos section to the third slide of the presentation
Steps:
click on the plus icon at the bottom of the screen to add new slide in presentation
choose first option ( Title slide) at top of the screen to insert a video
click on the square icon at lower left corner of the screen to insert a video 
swipe down the pop up window at the screen to view more options 
swipe down the pop up window at the screen to view more options 
choose video button on the pop up window at bottom  of the screen 
choose camera option at top of the screen to insert video 
choose first option at top of the screen