🔒 Switch on the lock icon at the bottom-left of the preview. Settings then stay put while you scroll.
6 · Export
1080×1920 (9:16) · H.264 MP4 (Chrome / Edge / Android) with original audio. Export runs in real time and keeps going if you minimise the browser or the screen dims. Just don't close the tab or the app. Safari may give WebM. The app checks the audio after export.