I don’t see any way to mark things 8va.
The original score has this section in Treble clef, which I could do, but marking as 8va would be better for other things.
Using tags and descriptive topic titles will probably help get answers. Post edited
As of 14.0.10, you should be able to create them from the clefs panel in the symbol palette.
Stefan,
Thanks! I found it. It is a bit challenging to adjust the range… but I did get it.