Playing 5 notes as 4 notation (insert correct Italian term)

I can't even recall what to call it, so I can't google it! I'm sure there's an Italian name for this somewhere.

This! The slur with the numbers to change the timing. This harp piece where 5, 6 or 7 notes are played across the space of 4. My question is not the name, although that's helpful, but how do I achieve this in MuseScore?