The Apply to Cue button is under the Home Tab on the ribbon when you are selected on a Main Text Box. It will not be available if you are selected on any other object (Reference Box, Background, Text Box, etc.). Can you verify that you are selected within the Main Text box of a multi page cue. Feel free to take a screenshot of your Home Tab Ribbon to show that the button is missing.
If you need to make an adjustment on just one of the pages, first set all pages by clicking Apply to Cue under the Home Tab. Then, go to the page that needs to be different and make your change WITHOUT clicking the Apply to Cue button.
Please let me know if this is not what you are seeing or if you are having further trouble with any of this.