Keep text overlays and the product inside the safe margins below. When the brand runs your content as an ad, buttons and captions appear over the edges, and anything outside the safe area can get covered.
When you upload a Reel or a Story, The Cirqle shows your content in each ad placement under "Verify ad placements". Check that nothing important is cropped or covered:
All good? Click "Nothing is obscured".
Something's covered? Click "I need to make changes", fix it and upload it again.