You've got three levers for changing creatives on a live ad: add new ones, pause individual creatives that aren't pulling their weight, or stop us from generating more automatic videos.
Add new creatives
Open your ad, head to the Visuals tab, and either upload a new MP4 or use Ads Studio to make one on the spot. Same specs as the initial setup (MP4, square or vertical, ideally 1080 wide × 1920 high, 7+ seconds, with audio).
New uploads go into the rotation with the rest, and Meta will start favoring the ones that perform best. If your ad has been running for a while and one or two existing creatives are clearly under-performing, adding fresh variations gives Meta more options to try. More variety tends to beat obsessing over a single hero video.
Pause individual creatives
Each creative in the Visuals table has a status toggle (ACTIVE / PAUSED). Toggle anything you don't want spending. The first toggle of the session shows a warning that Meta's learning phase may reset for a couple of days. After that we trust you.
Stop us from generating more automatic videos
By default we keep testing new auto-generated creatives during your campaign to boost engagement. If you'd rather we stop, flip the "Disable automatic videos" toggle in the Visuals section. Your existing creatives keep running and you can still upload your own; we just stop adding new generated ones to the mix.