Help with notation

How do I add other notes along with a whole note? I do not want to make a chord and the notes need to be played while holding the whole note but I can't get around the program automatically moving onto the next measure. I've also tried building the measure with a quarter note instead and then trying to replace it with a whole note however it completely deletes everything else in the measure. Is there something I'm missing or is the program currently unable to do this?

the photo attached to give an idea of what I'm looking for. I want to build the circled measure similar to the previous measure but with a whole note where the arrow is pointing.