But note you normally don't have to do anything special to create these - MuseScore creates them automatically when you generate prts from a full score. The only situation you would normally need to do this manually is if for some reason you are entering a single part only and not the rest of the score it comes from.
Comments
See:
https://musescore.org/en/handbook/measure-rests#multi-measure-rest
Typing 'M' toggles multi-measure rests on/off.
But note you normally don't have to do anything special to create these - MuseScore creates them automatically when you generate prts from a full score. The only situation you would normally need to do this manually is if for some reason you are entering a single part only and not the rest of the score it comes from.