A Microsoft file hosting and synchronization service.
Hello, thank you for reaching out to Microsoft Q&A.
OneDrive does not currently offer an option to back up only videos from your iPhone Photos folder. If you turn the Camera Backup feature On, all photos and videos in that folder will be backed up.
OneDrive does provide an option to exclude videos from the backup, but there is no setting to exclude only photos and back up videos alone.
To suggest this as a new feature to Microsoft, you can submit feedback through the OneDrive app on your iPhone, tap your profile picture, and select Help & Feedback to send your suggestion.