First step: Make sure you have a current treatment. For that, go in the “Treatments”-tab (3rd tab at the bottom) and check that you have a current treatment.
Second step: Tap on “Add reminders“. From there on, it should be easy.
It might take 1 day to be fully operational.
In the “Diary” (2nd tab at the bottom), you will see your intake times/reminders that you set up. By tapping on them, you can add the effective intake time. This is useful if you want to test different intake times for example.