1) Upload your MP4 video file. The file must weigh less than 3.5MB. This is to avoid "Heavy Ads Limitations" by the browser, which can cause the creative to either be rendered blank or be removed altogether.
2) Remember that the video should have an aspect ratio: 9:16
Disclaimer: The shown key-message visibility zone is only guaranteed when the viewport of the user follows the 9:16 aspect ratio.
Please note that unlike HTML, video material isn’t fully responsive. For this reason we recommend placing text, logo’s, buttons and anything else of importance in the middle of the creative, rather than close to the boundaries of the safezones.