For Waymark video's in Draft
You can edit your AI generated videos by going into your campaign's creative section.
Click "Edit" on the right side of the creative that you'll like to edit.
Once page opens then click "Next" in the blue bottom right corner.
Make your required edits to the creative.
Click the blue "Finish" button in the top right.
Wait for your video to finish processing.
For Waymark video's that are Active
For video's that have been approved and are currently active you will need to create a "+New Creative" to upload a new video or generate a new video.
If your video has been created within the last 30 days it will be saved to your recent history allowing you to edit the video you originally submitted.