Why MusicXML is the best file to bring
MusicXML carries the notes, the bars, the key and the layout of the parts exactly, so there is nothing to guess and the video starts out right.
Long scores work too: pick the parts you want on screen with the chips, since a full orchestra rarely fits a phone.
Exporting from MuseScore: File, Export, MusicXML. From Sibelius, Finale and Dorico the option has the same name, under Export.