Up stem voice starting with bar rest

In polyphonic music I’m inputting a down stem voice as the first entry. I would like the up stem voice in the treble clef to have a whole bar rest in the first bar. How do I do this?

Invoke the caret at the beginning of the piece, make sure the upstem voice is selected (little orange note in the caret), shift B and write rest in the popover. This does not work if the voice is empty, but once you have started writing something later, it should work.