This app follows your device's time format setting, so you need to change it in the Settings app.
Open your device's Settings app and change the setting as follows.
▼
Settings app → General → Date & Time → turn off "24-Hour Time"
This app follows your device's time format setting, so you need to change it in the Settings app.
Open your device's Settings app and change the setting as follows.
▼
Settings app → General → Date & Time → turn off "24-Hour Time"