Imagining using this 3-page design makes me feel uncomfortable at step 2 and 3. What if I didn't know what the "test" notification was supposed to look like and wanted to make sure the system took my input correctly? What if it's such a dire emergency that the operator forgets (perhaps from experiencing intense anxiety) which one was selected? I think a stronger approach would be to flatten the design to one page. You could then visually confirm that you've chosen a test/real alert, which alert was chosen, and then see what those options actually produce. In addition, because of the seriousness of sending an alert, I think it would be better to make the "Yes, Send Now" button harder to engage — maybe a slide to send, press and hold to send, or simply give a confirmation dialog after clicking it would help.