Há duas maneiras de verificar novas atualizações.
Verificar atualização...
Now MuseScore will check for updates on every start and notify you, if need be.
Select Help → Check for Update
A dialog will appear with the update status: either "No Update Available" or "An update for MuseScore is available:" followed by a link to download it.
Note: This menu option is only available in the Mac and Windows versions of MuseScore, as those can be updated directly from MuseScore.org. Linux distributions have different mechanisms to make updates available.