Oy. Lemme see if I can explain, I am not good at screenshots.

When you highlight a word or phrase, you get a small black box above the highlight. There is a symbol on the far right of it which shows a speaking bubble with lock inside. That’s your DM function. I apologize if it’s not clear. Typically at least for me, I highlight the word or phrase first, then when I click on it again, I see all four options the DM on the far right of the icons.