Also, if you go to the "Edit" menu, under "Measure", you'll see "Delete Selected Measures", with "Ctrl+Del" listed as the shortcut. Most commands in MuseScore that have keybaord shortcuts can also be accessed with menus that tell you the shortcut (there are some exceptions). When in doubt, see the Handbook. In this case, the answer is found under "Measure operations".
Comments
Select measures.
Ctrl-delete.
Also, if you go to the "Edit" menu, under "Measure", you'll see "Delete Selected Measures", with "Ctrl+Del" listed as the shortcut. Most commands in MuseScore that have keybaord shortcuts can also be accessed with menus that tell you the shortcut (there are some exceptions). When in doubt, see the Handbook. In this case, the answer is found under "Measure operations".
See https://musescore.org/en/handbook/measure-operations-0#delete