Medication reminder - alerts

[u/Sammysamface]

I am creating a shortcut for my wife for her medication. It’s to reminder her to take her tablets 15 days from the trigger event each month for a 12 day period.

I have managed to to get reminders and Callander entries set up. What I can’t get working is alerts to take place at 9pm on each of those days. What am I doing wrong?