By default, Rolla does not allow users to upload clips from their camera roll. This is to ensure all video clips submitted to Rolla are quality, by using Rolla's capture guidance.
That being said, upon request we can update your profile to allow you to access your camera roll for specific projects.
Once activated:
Go to your specific project you want to add clips to
Hit the plus button in the specific scene you want to add clips to
Select the Upload from Camera Roll button to select and upload your clips