How do I cure a Citizen with a Treatment during dialogue?

In the Chapter II quest "Night Shift" you have to create a Treatment for fatigue and then bring it to a nurse to treat a patient. The quest is marked as complete as soon as you talk to the nurse (the last checkbox is "Bring the medicine to the nurse in the patient's room"), but the patient is not cured and the Treatment is still sitting in your inventory. If you want to actually heal the patient (and get XP for doing so), or any other Citizen, you have to actually give them the Treatment. What button do I press to do that?

I can't see any prompt to do so either during conversation or before/afterward. I've revisited every dialogue tree twice just to make sure. I did the same thing with another nearby patient who happens to need the same Treatment -- same issue.

Ah, it's cleverly disguised under the wording "Medical Check-Up" in the upper right corner. On PS4 that's R1 bumper. This causes you to utter some filler (and not subtitled, at least in this one case) dialog, at which point you can then choose to give or withhold the medicine.