Hello on the MUSESCORE site there are 4 small squares on the top right which allow the full screen display of each sheet. On all AZERTY keyboards there is also a PRINT SCREEN key on the top right. The combination of all this is already the first tip. Then there is a small program called PICPICK https://www.clubic.com/telecharger-fiche308612-picpick.html which also exists for smartphones and allows to make a burst screen capture, so you can capture all the sheets of a score always displayed in full page mode with the 4 corners icon. And then there is also an extension for browsers that allows you to retrieve everything from Musescore (I can't tell you more).