How to play Apple 1 1 original camera in slow motion?

Slow motion: after filming, I want to slow down a certain action.

Turn on the camera of iPhone 1 1, then slide your finger from left to right twice in the lower operation bar to enter the time-lapse photography interface.

After entering the time-lapse photography interface, click the red dot below to start photography, and click the red square below to end photography after photography to complete a time-lapse photography.