How to write ...

It's a bit laborious to do:
1. Create a Staff Text, fill it with spaces to extend it across the empty measure(s).
2. Turn off Autoplace for the Staff Text.
3. Edit the Staff Text and press Enter a few times to get the box height correct.
4. In the Properties panel for the Staff Text, click "More...) to reveal the Frame options.
5. In the Properties panel for the Staff Text's Frame options:
- choose the rectangular frame shape
- change the frame's Border colour to red
- increase the frame's Thickness property