Open the Photos app
Select the photos you want to use
Tap the Share button
Tap Slideshow
Tap Options to adjust theme, music, and speed
Tap Play to preview the slideshow
To save as a video, open the Photos app and select the photos
Tap Add to Album if needed to organize them first
Open the iMovie app
Tap Create Project
Tap Movie
Select the photos you want to include
Tap Create Movie
Rearrange the photos if needed
Add transitions, text, and music if desired
Tap Done
Tap the Share button
Tap Save Video
Choose the video quality
Wait for the video to export to your Photos app