extending width of a single measure

Today during a mastering musescore cafe I presented a problem where a long chord symbol crashed into a bar line of the next measure (in a teaching sheet where chords symbols were in a staff) and thus making it impossible to move the chord symbol up or down easily.

The simple answer was to simply widen that measure with the long chord symbol, but I can't remember the command on how to widen a single measure. tried searching handbook, but not hitting the correct search term. TIA!