Set reminders where they help you act. A meal reminder can fit the start of your lunch break; a bar reminder can come near the craving window you identified, while the portion is still easy to have ready.
If your day changes, review the plan and reminder options in the app. Move the timing to match your actual meals and snack window. If you cannot find an option, ask support rather than assuming the sample schedule is compulsory.
For phone alerts, also check the appās notification permissions in your device settings. Changes to reminders and meal timing do not automatically change subscription quantities or deliveries.