Note/rhthym proportionality between sections

I want to indicate that after a time signature change, a measure should be played such that the beat of a half note becomes a dotted half note. I've seen in scores this is usually indicated with an equal sign between the previous note value and the next section note value. This is usually located above the staff. How do I do this in Musescore?

I tried searching but probably don't have the correct music terminology!