You can add a transition between each media and chapter as shown below:
Step 1: Sharing a prompt when creating the video
Step 2: Sharing a command via the magic box
Changing it manually from the settings option as shown below:
1) Click on Edit
2) In media properties, you can adjust the settings for individual media.
3) In settings, you can change the transition for the entire video.
Click on save changes once done!